Fee unit tests

[grarco]

Describe your changes

Adds a new unit test to verify that the fee payment is committed even in case the inner tx failed (wasn't needed before the tx queue removal pr).
Improves the insufficient_balance test to have an initial balance.

Indicate on which release or other PRs this topic is based on

#2819 (diff: 4219d74) rebased on top of v0.31.9

Checklist before merging to draft

• I have added a changelog
• Git history is in acceptable state

[codecov]

Codecov Report

Attention: Patch coverage is 68.42105% with 192 lines in your changes are missing coverage. Please review.

Project coverage is 53.57%. Comparing base (2ba001d) to head (ba6f1c3).
Report is 135 commits behind head on main.

Files	Patch %	Lines
crates/sdk/src/masp.rs	0.00%	95 Missing ⚠️
...s/apps/src/lib/node/ledger/shell/finalize_block.rs	88.23%	18 Missing ⚠️
crates/apps/src/lib/bench_utils.rs	0.00%	16 Missing ⚠️
crates/sdk/src/tx.rs	0.00%	14 Missing ⚠️
...ates/apps/src/lib/node/ledger/shell/block_alloc.rs	89.47%	12 Missing ⚠️
crates/apps/src/lib/client/rpc.rs	0.00%	8 Missing ⚠️
crates/apps/src/lib/node/ledger/shell/mod.rs	36.36%	7 Missing ⚠️
.../apps/src/lib/node/ledger/shell/vote_extensions.rs	66.66%	6 Missing ⚠️
...apps/src/lib/node/ledger/shell/process_proposal.rs	77.27%	5 Missing ⚠️
...tes/apps/src/lib/node/ledger/shell/testing/node.rs	0.00%	3 Missing ⚠️
... and 8 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2914      +/-   ##
==========================================
- Coverage   53.88%   53.57%   -0.31%     
==========================================
  Files         308      307       -1     
  Lines      100154    99229     -925     
==========================================
- Hits        53966    53163     -803     
+ Misses      46188    46066     -122     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.