[EVM] Add pending nonce expiry for safety

[stevenlanders]

Describe your changes and provide context

• This adds a safety behavior where pending nonces disappear if not addressed for a minute
• Since transactions should expire after 30s anyway, this just ensures we don't have orphaned nonces

Reasons for this

• There are a number of cases where a remove-nonce callback might not be called, including various error cases in the mempool
• There are cases where it isn't clear whether a remove-nonce callback should be called. For instance, a duplicate may be found before the previous nonce has been cleared (we don't want to clear the previous tx's nonce)

Testing performed to validate your change

• Unit Test
• Lower environment deployed with load test

[codecov[bot]]

Codecov Report

Attention: 19 lines in your changes are missing coverage. Please review.

Comparison is base (58dcc69) 63.27% compared to head (0356dcb) 63.04%. Report is 1 commits behind head on evm.

Additional details and impacted files

@@            Coverage Diff             @@
##              evm    #1321      +/-   ##
==========================================
- Coverage   63.27%   63.04%   -0.23%     
==========================================
  Files         346      347       +1     
  Lines       23357    23517     +160     
==========================================
+ Hits        14779    14827      +48     
- Misses       7746     7855     +109     
- Partials      832      835       +3     

Files	Coverage Δ
app/app.go	68.78% <100.00%> (ø)
x/evm/keeper/keeper.go	85.31% <74.66%> (-3.77%)	:arrow_down:

... and 4 files with indirect coverage changes