pindexer: implement override for hardcoded values in app views

[cronokirby]

Describe your changes

This adds two flags:

 --indexing-denom <INDEXING_DENOM>
            The denom to use for indexing related components, of the form passet1... [default:
            passet1w6e7fvgxsy6ccy3m8q0eqcuyw6mh3yzqu3uq9h58nu8m8mku359spvulf6

for setting the denom used for indexing (instead of USDC)

and

--dex-ex-min-liquidity <DEX_EX_MIN_LIQUIDITY>
            The minimum liquidity for the indexing denom in the dex explorer app view [default:
            100000000]

for overriding the minimum liquidity in terms of that asset for a pair to be considered in the aggregate dex explorer summary.

Closes #4920.

For testing, we can try running this against the testnet with different values.

Checklist before requesting a review

• I have added guiding text to explain how a reviewer should test these changes.

• If this code contains consensus-breaking changes, I have added the "consensus-breaking" label. Otherwise, I declare my belief that there are not consensus-breaking changes, for the following reason:

  indexing

[conorsch]

Rebased on latest main (ad95d8c) to include #4934, to make testing this more straightforward.