[mock-chain] add new transaction checks

[arobsn]

• [ ] Check min nenoergs per box
• [ ] Check for miner fee box inclusion and if fee per byte threshold is met
  • [ ] allow customized fee trees
  • [ ] allow disabling this check

[AdityaGupta20871]

@arobsn I have been working on this issue Can I open a PR for this?

[arobsn]

@AdityaGupta20871 sure, go ahead!