Add C# client SDK procedures (#3666)

# Description of Changes

Closes: #3533 
Updated the C# SDK to handle procedures and procedure callbacks in a
similar fashion to the Rust client as well as added the codegen to
support it.

# API and ABI breaking changes

N/A

# Expected complexity level and risk

2 - This adds a new testing frame that should be removed once procedures
are handled with C# module bindings

# Testing

Added /sdks/csharp/examples~/regression-tests/procedure-client to match
modules/sdk-test-procedure which we can roll into the standard
regression-tests once C# supports the procedure attribute.

- [x] Add C# client test of sdk-test-procedure

---------

Signed-off-by: Jason Larabie <jason@clockworklabs.io>

Author: JasonAtClockwork