Compute max fees for transaction related requests and display the
results to user.
Also:
- Add helper to convert from hex (backend) to decimal (frontend) values.
- Add helper to convert from float gwei to hex wei
- Update tests to accommodate for the new dependencies.
Sourcing of account balances is not included therefore the transaction is
allowed to go through even if the account balance is insufficient. An error
will be generated by the backend in this case.
Updates: #15192
248ba1c1c8