Port transaction validation tests to new function

[arnetheduck]

nimbus-eth1/nimbus/transaction.nim

Line 157 in d6eb8c3

proc validate*(tx: Transaction, fork: EVMFork) =

contains a transaction validation function that has fallen out of use.

The old function however has a set of checks and validations that the new function does not have - it also has test coverage which is missing from the new function - both of these issues need to be address such that the old tests and validations are checked.