Pact 4.7 Release Prep

[emilypi]

This PR is for the relevant prep and tracking needed for the Pact 4.7 release.

• Changelog updated
• Version changed
• Docs generated
• All relevant PRs are in

Relevant PRs

Merged:

• Runtime check for return types: [FORK] Add runtime type check for function return types #1209
• Native Versioning: Native versioning in EvalEnv #1195
• Implement dec for integer to decimal coercion: Implement 'dec' for converting integers to decimals #1150
• Implement shift natives in terms of other natives: Implement the shift native in terms of other natives #1208
• Forked errors on-chain: Forked errors on chain #1185
• Don't display function docs in non-repl context: Forked errors on chain #1185
• Allow Namespaces to reset to root: Add support for resetting the env namespace #1174
• Read-msg recovers on non-existent key: read-msg recoverable under some key #1223

Moved to Next Service Date:

• Transcendental functions using native Haskell: Implement transcendental functions using decimal-arithmetic Haskell library #1204
  • Gas accounting: Add gas to decimal-arithmetic #1217
  • Benchmarks pending

[imalsogreg]

LGTM