Implement I/O gas measurement

[freesig]

• Add witness data limit via transaction policies
  • spec PR Transaction Policies fuel-specs#514.
  • vm issue Support Transaction Policies fuel-vm#576.
  • Implement refund for unused witnesses limit
• Determine appropriate gas per byte #1404
• Increase the cost of storage opcodes by the gas per byte fee in addition to the execution cost fuel-vm#602

Acceptance Criteria:

• Witness data is included in the base transaction fee for bytes
• Witness bytes can't exceed the witness data limit policy (if set)
• Storage read/write costs are adjusted to constrain excessive state growth long-term

[xgreenx]

All sub-issues are resolved