This commit introduces E2E test that checks the functiolality of
verified/unverified tokens. Following general steps are executed:
1. Import account
2. Enable `Show unverified assets`
3. Hide asset
4. Trust asset
5. Hide trusted asset
A number of checks is performed during each step.

The commit also introduces helper functions and adds `data-testid` attribute to
a couple of DOM elements.

As some of the code is similar or identical as in the
#3418 PR which is yet not merged to
`main`, some conflicts may arise and will need to be resolved before this change
lands on `main`.

Also some changes will need to be made once
#3195 gets merged to `main`, as this
PR solves a bug causing failures in the tests (the failing part of the test was
temporarily commented out).

The steps were temporarily commented out because there was a bug that caused the
step to fail. Now that the bug got fixed, we can uncomment.

We want to have a control over the account we use in test, as change in the
state of the assets may break the tests. We'll use the account with the address
0x6f1b1f1feb01235e15a7962f16c389c7f8218ed6` (`e2e.testertesting.eth`).

We also fix some flakiness and improve the locators used in tests.

We're removing some code that became unnecessary after the merge from `main`.
We're also switching from onboarding using seed phrase to onboarding using JSON
file with encrypted private key.

Previous implementation wasn't properly handling cases when the assertion was
not met. In such cases it was silently ending the tests, without reporting any
failures (the failure was visible only in the Playwright report, which wasn't
opened by default).

We had a bug in the code that was resulting in price of some assets not being
displayed. We've temporarily commented out the assertions that verify this. Now
that the bug is fixed, we can uncomment.

The `assertAssetDetailsPage` function was a more robust version of the
`verifyAssetActivityScreen` function. When `verifyAssetActivityScreen` was
created we didn't yet have the `AssetsHelper` so we kept the function checking
the activity detais in the `TransactionsHelper`. Now that we have a specific
helper for assets, we can merge both functions into one.

Comment suggested that we could move some of the functions from `AssetsHelper`
to `TransactionsHelper`. After thinking it through, I think it makes sense to
leave the functions where they are, especially that they're used not only during
filling of the Transaction form but also during filling of the Swap form.

We're adding a timeout, as switching to the Polygon network too fast after
importing wallet was causing some of the price info missing for the ERC-20
assets. It's quite unlikely for the real users to switch the network this fast
anyway, so the timeout does not contradict the real user behaviour.

We changed this for production fork builds to differentiate from the release
builds, and we updated e2e tests to look for the suffix, but on non release
branches the fork builds were not getting the suffix, leading to test failures.

The previously used 1s wait sometimes wasn't sufficient.

The checks are no longer failing. What fixed them is not known, but maybe it has
something to do with the wait period added before switching to Polygon.

As we have functionality of verifying assets in the wallet, we recently started
to use `assert` nomenclature in the names of the new functions and methods
checking certain areas of the wallet. This was done to avoid confusion in the
naming. Now we update the older function using the `verify...` prefix, to make
the naming consistent across all our test-related files.

The steps were added temporarily for debugging purposes, but accidentally got
commited.

As after opening the Accounts list, there were multiple `slide_up_menu`
elements in the wallet's DOM, and only one was not of a `closed` class, we were
using the `ElementHandle` syntax to find the one which is not closed (the one
we wanted to click). This then influenced the way how we can locate the `Close
menu` button, making the code quite complicated.
In this PR we are simplifying the code, by filtering the slide up menus by the
`Accounts` text. Then we are able to point to the right `Close menu` element by
using `.first()` locator.

Both functions are currently not used by the e2e tests, but we want to keep
them in case they're needed in the future. We're moving the steps closing the
Accounts slide up to the `addAddressToAccount()` functions for now. They may be
separated on the future, if there will be a need for this.

There may be a situation where we have a spam asset named the same as the
asset we verified and are checking in the `assertVerifiedAssetOnWalletPage`
function. The previous implementation of the function wasn't supporting such
case. Now the function should handle it.

We've pulled some of the code relating to JSON onboarding reused in several
tests to a `WalletPageHelper`'s `onboardWithJSON` method. Now the onboarding
with JSON in e2e tests requires just one command:
`await walletPageHelper.onboardWithJSON(<account>)`,
where `account` can be either `account1`, `account2`, or `custom`.
The `account1`'s and `account2`'s JSON data (body & password) is accessed via
the `onboarding.ts` file. The `custom` option allows for onboarding wit a custom
account and requires providing the `customJsonBody` and `customFilePassword`
parameters.

So far we've been storing each piece of the account-specific data in a separate
variable. We are now reorganizing the data into objects adhering to a common
interface structure.