op-service/txmgr: multiple fixes / improvements

[roberto-bayardo]

Description

• have transactions get resubmitted even if we fail to bump fees to prevent indefinite hanging when a tx gets dropped from the mempool (as experienced by both base-sepolia and op-sepolia on 8/27/2024).

• do not bump fees in response to errors that do not require fee bumping like nonce-too-low.

• force a critical error if we get nonce-too-low before successfully publishing a transaction so the nonce state will reset before trying to publish another transaction.

• force a critical error if the context is cancelled so the send aborts immediately.

• some control flow refactoring to (hopefully) make the code a bit more understandable.

Tests

fixed existing unit tests that were relying on fee bumping when fees shouldn't have been bumped, and added new test for the immeidate-fail-on-nonce-too-low case.

TODO:

• add test to ensure tx gets resubmitted even if fees can't be bumped.
• add test to check that context cancellation causes the send to abort immediately.

Additional context

Metadata

• Fixes #[Link to Issue]