[tasks] Add auto runtime initialization template to LibraryBuilder

[mdh1418]

Contributes to #79377

Incorporates mono's lazy runtime init capability #82253 into the library builder task #81919.

In the target use case of having a self-contained library containing the mono runtime with custom managed code, the mono runtime needs to be initialized when the library is loaded into the native application. In order to do so, one can either

A. leverage the default runtime-init-callback and upon loading the shared library, rely on the auto initialization logic in autoinit.c (Introduced by this PR) to setup the callback via mono_set_runtime_init_callback. The callback is set when first loading the shared library due to the constructor.

or

B. pass in a custom runtime-init-callback= introduced in #82253 and have one's own runtime initialization startup logic instead of autoinit.c.

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The runtime initialization logic looked at https://github.com/dotnet/runtime/blob/main/src/tasks/AndroidAppBuilder/Templates/monodroid.c for inspiration.
In attempt to have a barebones version, the following is done:

• Set the path to assemblies, expected in environment variable DOTNET_ASSETS_PATH
• Initialize possible runtime config file
• Initialize app context environment variables
• register all aot modules
• register bundled modules // TODO when bundling is implemented
• set the path to search for assemblies based on environment variable DOTNET_ASSETS_PATH or custom defined variable
• set to aot only // For now until Mixed mode is worked out
• add a custom assembly preload hook // No longer needed as assembly paths are set
• allow for debugging //TODO in followup
• add install hook for aot data // Not default scenario
• add signal chaining
• initialize the mono runtime
• load all assemblies that contain exported symbols

---

Example generated files
CMakeLists
shared_library_log.h
autoinit.c
load_assemblies.c

[mdh1418]

From the Build Analysis, looks like everything is a known test error.
Unfortunately I made a slight typo and I need to update the CMake, but that shouldn't affect any of our tests.

[lateralusX]

LGTM!

[mdh1418]

All failures are known issues.