Move payment driver config & database to yagna data directory

[kamirr]

Acceptance critera:

• Put erc20_payment_lib database in yagna data dir
• Have the default config compiled into the source code & allow overriding the individual settings via ENV variables for each chain. Only expose:
  • rpc-endpoints
  • priority-fee
  • max-fee-per-gas
  • token.address (required by goth)

[kamirr]

The change in yagna is a part of the PR that enables testing because it already has to deal with ENV variables set by goth, so splitting that into separate PRs would add more pointless work.