feat(csharp): add map type support #3897

Job	Run time
Verify MSRV	1m 2s
clippy	56s
Check	2m 44s
verify-publish	2m 49s
Crate Unit Tests	2m 33s
Test Async (allowed to fail)	2m 43s
Rustfmt	16s
Build wit-bindgen (aarch64-macos, macos-latest, aarch64-apple-darwin, 10.12)	3m 41s
Build wit-bindgen (aarch64-linux, ubuntu-latest, aarch64-unknown-linux-gnu, ./ci/docker/aarch64-l...	3m 11s
Build wit-bindgen (x86_64-windows, windows-latest, x86_64-pc-windows-msvc, -Ctarget-feature=+crt-...	4m 6s
Build wit-bindgen (x86_64-macos, macos-latest, x86_64-apple-darwin, 10.12)	2m 27s
Build wit-bindgen (riscv64gc-linux, ubuntu-latest, riscv64gc-unknown-linux-gnu, ./ci/docker/riscv...	2m 38s
Build wit-bindgen (x86_64-linux, ubuntu-latest, x86_64-unknown-linux-gnu, ./ci/docker/x86_64-linu...	2m 49s
Build wit-bindgen (aarch64-windows, windows-11-arm, aarch64-pc-windows-msvc, -Ctarget-feature=+cr...	3m 38s
Test (ubuntu-latest, csharp)	9m 14s
Test (ubuntu-latest, c)	1m 58s
Test (ubuntu-latest, cpp)	3m 30s
Test (windows-latest, csharp)	14m 49s
Test (ubuntu-latest, rust)	3m 3s
Test (macos-latest, cpp)	3m 46s
Test (macos-latest, rust)	3m 52s
Test (ubuntu-latest, go)	3m 59s
Test (windows-latest, rust)	7m 7s
Test (windows-latest, go)	7m 18s
Test (windows-latest, cpp)	5m 24s
Test (windows-latest, c)	4m 55s
Test (macos-latest, c)	1m 57s
Test (macos-latest, go)	3m 31s
Record the result of testing and building steps	2s
	1h 49m 58s

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