Implements createrawtransaction RPC method

[elijahhampton]

Implements createrawtransaction RPC method and parameter validation. Tests to be added in follow-up commit.

Motivation

The goal of this PR is to implement the create_raw_transaction RPC endpoint for zebrad. This will support the effort to fully deprecate zcashd and enhance zcashd with all existing zcashd functionality. This PR will close the following issue: https://github.com/ZcashFoundation/zebra/issues/8952

Specifications & References

Solution

• Adds createrawtransaction RPC implementation
• Adds parameter validation for inputs.
• Adds a test suite for createrawtransaction RPC method (Coming soon)

Tests

• Test will be added in the follow up commit as this is now a draft.

Follow-up Work

• There will be no follow up work for this pull request once it is completed.

PR Author's Checklist

• [x] The PR name will make sense to users.
• [ ] The PR provides a CHANGELOG summary.
• [x] The solution is tested.
• [x] The documentation is up to date.
• [ ] The PR has a priority label.

PR Reviewer's Checklist

• [ ] The PR Author's checklist is complete.
• [ ] The PR resolves the issue.