Aave v3 transaction actions indexer

[varasev]

Motivation

This PR adds handlers for transaction actions of Aave v3 protocol. Doesn't require changes in API v2 (all tx actions are already supported by API).

Includes changes for the old UI. Example:

Checklist for your Pull Request (PR)

• I added an entry to CHANGELOG.md with this PR
• If I added new functionality, I added tests covering it.
• If I fixed a bug, I added a regression test to prevent the bug from silently reappearing again.
• I checked whether I should update the docs and did so by submitting a PR Add env variable for Aave v3 transaction actions docs#130
• If I added/changed/removed ENV var, I submitted a PR to https://github.com/blockscout/docs to update the list of env vars at https://github.com/blockscout/docs/blob/master/for-developers/information-and-settings/env-variables.md and I updated the version to master in the Version column. Changes will be reflected in this table: https://docs.blockscout.com/for-developers/information-and-settings/env-variables.
• If I add new indices into DB, I checked, that they are not redundant with PGHero or other tools

[vbaranov]

I would suggest to finalize #7107 first: there is an open question #7107 (review), and create these changes in PR against master branch - I assume there will be errors in Spelling CI because "aave" has not been added to dictionary.

[varasev]

I rebased it onto va-tx-actions-improvement