Add support for the official Wasm C-API

[Robbepop]

Closes #922

This is going to be a larger effort and low-priority so I will be working on it from time to time.
Inspired by: https://github.com/bytecodealliance/wasmtime/tree/main/crates/c-api/

TODO

Chores

• Doxygen Docs
• Cmake Installation
• CI Integration
  • Build & Install via CMake
  • Generate Doxygen Docs via CMake
  • Format C Headers via CMake
• README

Implementation

• wasm_config_t
• wasm_engine_t
• wasm_store_t
• wasm_module_t
• wasm_instance_t
• wasm_trap_t
• wasm_byte_vec_t
• wasm_func_t
• wasm_functype_t
• wasm_functype_vec_t
• wasm_table_t
• wasm_tabletype_t
• wasm_tabletype_vec_t
• wasm_memory_t
• wasm_memorytype_t
• wasm_memorytype_vec_t
• wasm_global_t
• wasm_globaltype_t
• wasm_globaltype_vec_t
• wasm_byte_vec_t
• wasm_extern_t
• wasm_externtype_t
• wasm_externtype_vec_t
• wasm_importtype_t
• wasm_importtype_vec_t
• wasm_exporttype_t
• wasm_exporttype_vec_t
• wasm_frame_t
• wasm_frame_vec_t
• wasm_val_t
• wasm_val_vec_t
• wasm_valtype_t
• wasm_valtype_vec_t
• wasm_ref_t
• wasmi_error_t

Follow-up PRs

• wasmi_linker_t
• wasmi_caller_t

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 196 lines in your changes missing coverage. Please review.

Project coverage is 80.10%. Comparing base (3d7f8be) to head (a9f2524).

Files	Patch %	Lines
crates/c_api/src/val.rs	0.00%	34 Missing ⚠️
crates/c_api/src/types/func.rs	0.00%	18 Missing ⚠️
crates/c_api/src/types/memory.rs	0.00%	17 Missing ⚠️
crates/c_api/src/types/table.rs	0.00%	16 Missing ⚠️
crates/c_api/src/types/global.rs	0.00%	15 Missing ⚠️
crates/c_api/src/ref.rs	0.00%	14 Missing ⚠️
crates/c_api/src/func.rs	0.00%	11 Missing ⚠️
crates/c_api/src/global.rs	0.00%	11 Missing ⚠️
crates/c_api/src/memory.rs	0.00%	11 Missing ⚠️
crates/c_api/src/table.rs	0.00%	11 Missing ⚠️
... and 11 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1009      +/-   ##
==========================================
- Coverage   80.72%   80.10%   -0.63%     
==========================================
  Files         274      295      +21     
  Lines       25173    25369     +196     
==========================================
  Hits        20322    20322              
- Misses       4851     5047     +196     

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[Robbepop]

We probably need to do something similar here to enable LTO builds for the artifacts later: bytecodealliance/wasmtime#7341

However, I'd put the implementation into an impl folder and use root for the wrapper crate instead of the reversed approach as taken by Wasmtime.

[Robbepop]

This is currently blocked by Wasmi having no built-in support for Instance::new instance creation as in Wasmtime: https://docs.rs/wasmtime/23.0.1/wasmtime/struct.Instance.html#method.new

This API is mandated by the Wasm C-API.