Mesh 1929/fix transaction state rollback

[HenriqueNogara]

Adds an event for failing to execute an Instruction. To avoid rolling back the state (once the code is updated to the new substrate version) the result of execute_instruction_retryable is now matched

changelog

modified API

• Adds an event: FailedToExecuteInstruction;
• execute_scheduled_instruction will no longer return an error;

modified logic

• To avoid a state rollback (i.e allow setting instruction status to the failed state) the return of execute_instruction_retryable is now matched, and returns an event in case of failure.

[codecov]

Codecov Report

Merging #1383 (6fd9184) into develop (b011077) will decrease coverage by 0.09%.
The diff coverage is 0.00%.

@@             Coverage Diff             @@
##           develop    #1383      +/-   ##
===========================================
- Coverage    43.34%   43.26%   -0.09%     
===========================================
  Files          140      140              
  Lines        30132    30136       +4     
===========================================
- Hits         13060    13037      -23     
- Misses       17072    17099      +27     

Impacted Files	Coverage Δ
pallets/settlement/src/lib.rs	45.43% <0.00%> (-1.76%)	⬇️
primitives/src/asset_identifier.rs	97.92% <0.00%> (-0.42%)	⬇️