make it clear that MaxFee field is not used anymore for V3 tx + improve comments for Transactions

[TAdev0]

Closes #2129

also reorganize fields to make it clearer in general

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.31%. Comparing base (71c7ca2) to head (299f1e3).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2130      +/-   ##
==========================================
- Coverage   78.33%   78.31%   -0.03%     
==========================================
  Files         100      100              
  Lines        9221     9221              
==========================================
- Hits         7223     7221       -2     
  Misses       1357     1357              
- Partials      641      643       +2     

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