Implementation of the Native Introspection proposal

Summary

Implementation of the Native Introspection Opcodes CHIP:

https://gitlab.com/GeneralProtocols/research/chips/-/blob/master/CHIP-2021-02-Add-Native-Introspection-Opcodes.md

About Int64 Integers

Please, we request to review the Int64 MR (!1253 (merged)) so we can merge it here.

Proposals and related talks

Consider the following sites where things about this proposal are discussed:

https://bitcoincashresearch.org/t/chip-2021-02-add-native-introspection-opcodes/307

https://t.me/transactionintrospection

Test Plan

• ninja all check-functional-extended
• Given the consensus-sensitive changes, it is recommended to run a full IBD in all possible networks. (with -assumevalid=0 to ensure all scripts are evaluated).

Acknowledgments

This MR was a work done together with @cculianu.