Fix websocket from_height

[codchen]

Describe your changes and provide context

To fix #1850

There is a bug in how fromHeight is set during the websocket handler loop. Specifically each iteration will only look at the latest height if we don't set filter.FromBlock to the last height handled by the last iteration, so in the case where multiple heights have passed between two websocket iterations, events would be lost.

Testing performed to validate your change

difficult to simulate latest height passing in unit test. Since this is an RPC-only change, we can apply it to the RPC node the bug reporter is using and see if the error is resolved

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 60.81%. Comparing base (e8e4b3b) to head (5cda988).
Report is 165 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1853      +/-   ##
==========================================
- Coverage   61.64%   60.81%   -0.84%     
==========================================
  Files         365      260     -105     
  Lines       26178    22869    -3309     
==========================================
- Hits        16138    13908    -2230     
+ Misses       8967     7976     -991     
+ Partials     1073      985      -88     

Files with missing lines	Coverage Δ
evmrpc/subscribe.go	63.40% <100.00%> (-0.81%)	⬇️

... and 192 files with indirect coverage changes