[ecash-agora] Prepare agora test framework to have more sats available

Summary:
To get better test coverage, it's necessary to have more sats available during testing.

This diff changes the blocks generated to the OP_TRUE address to 149, which covers the entire halving period, which gives us a little less than 7450M XEC, which is good enough.

Test Plan: npm run integration-tests

Reviewers: bytesofman, #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D16741