fixing tests

Revert "Switch all hex to bytes conversions to ethjs equivalents"

This reverts commit 040ff32933c5a9fb178d224c71f793fc25e2f1da.

Currently passing portalnetwork test and integration test, cli test still have 1 failed test. I'm not sure how to proceed from here.

Here is the failed cli test case:
```
 FAIL  test/rpc/portal/beaconLocalContent.spec.ts > portal_beaconLocalContent tests > should not find any local content
AssertionError: expected -32603 to equal -32009

- Expected
+ Received

- -32009
+ -32603

 ❯ test/rpc/portal/beaconLocalContent.spec.ts:20:12
     18|       ),
     19|     ])
     20|     assert.equal(res.error.code, -32009)
       |            ^
     21|     ultralight.kill(9)
     22|   }, 10000)
```