RPC poller is too verbose by default

[matthewdarwin]

Every time the RPC poller retrieves 1 block, it generates a lot of logs at the default log level. This is fine for debug logging, but by default it should be quieter.

This is especially important when catching up to chain head where you get many blocks/second.

2024-08-07T12:41:44.338Z INFO (fireeth) saved cursor {"filepath": "/var/lib/dfuse/poller-state/cursor.json", "last_fired_block": "21759727 (63952b37169e7f07a689185c8b9531189c305a0ea67241821de8f93e4bc55d3f)", "lib": "21759700 (5a8201f764f9000e068c0d7ae1b1f56d9c072df90865e11cce1c64e4358d7da0)", "block_count": 28}
2024-08-07T12:41:44.339Z INFO (fireeth) about to fetch block {"block_to_fetch": 21759728}
2024-08-07T12:41:44.339Z INFO (fireeth) requesting block {"block_num": 21759728}
2024-08-07T12:41:44.339Z INFO (fireeth) optimistically fetching block {"block_num": 21759728}
2024-08-07T12:41:44.439Z INFO (fireeth) block was optimistically polled {"block_num": 21759728}
2024-08-07T12:41:44.440Z INFO (fireeth) processing block {"block": "#21759728 (c588b8496a7cbb4e01b86a04bc347cd2e802e32b0bb8abe129b565b503c53146)", "lib_num": 21759528}
2024-08-07T12:41:44.441Z INFO (fireeth) saved cursor {"filepath": "/var/lib/dfuse/poller-state/cursor.json", "last_fired_block": "21759728 (c588b8496a7cbb4e01b86a04bc347cd2e802e32b0bb8abe129b565b503c53146)", "lib": "21759700 (5a8201f764f9000e068c0d7ae1b1f56d9c072df90865e11cce1c64e4358d7da0)", "block_count": 29}