Add IDF caching for libraries

[mikee47]

Cache esp-idf and tools for library builds. Be nice if we could use the cache from SmingHub/Sming directly but that sort of cross-repo sharing isn't supported.

Also discovered that cross-OS caching breaks because the cache action uses paths relative to the build directory, even though it's been given absolute paths. So, just simplify the thing and use a separate, combined cache for each OS/IDF combination. Total's about 5GB.

In all the .yml files we don't need to repeat steps for Ubuntu/MacOS as they're the same, so we can use a combined step for those, ie. not windows.

Scanlog tool:

• Fix scanlog tool windows path normalisation - didn't account for change from c:/tools/ to d:/opt/, and that Windows idf path contains version.
• Print warnings for each job by default, add 'm' flag to merge them

Also fix a few more warnings.

[what-the-diff]

PR Summary

• Enhancements Made to the GitHub Workflow
  A default value has been set for the 'INSTALL_IDF_VER' environment variable in the library.yml workflow file. This simplifies the handling of this varibale. The workflow now also takes care of fixing permissions on non-Windows systems. Additionally, enhancements have been made to cache ESP-IDF and IDF build tools for Esp32 architecture, improving efficiency and speed of development workflows.

• Codebase Clean-up
  Various unused parameters in functions across multiple files were found and removed. This includes setFileMap function in HttpMultipartResource.cpp, onStarted function in SwitchJoycon.h, decode function in Callback.cpp & InputStream::decode function in Stream.cpp, along with DummyOutputStream::write function in Stream.h and i2sCallback function in application.cpp in Basic_Audio sample. An unused function shutdown in HttpMultipartResource.h was also removed. This leads to cleaner code and fewer chances of misunderstanding and bugs.

• Documentation Update
  The README.rst file now includes additional details explaining how to use warnings output in Visual Studio Code. This makes understanding and handling warning outputs easier for users.

• Improvements in Scanlog.py
  Modifications were made in scanlog.py to introduce a new command-line argument -m, which enables merging of warnings from all jobs. The tools allows warnings output path replacement and removing prefixes. It will print merged or individual job warnings based on the -m flag. Also, it can now exclude warnings based on a list in a file, providing more control over warning management.

[mikee47]

I'm impressed with that summary from 'what-the-diff' - it's actually useful :-)

[mikee47]

Changing to WIP, library caching not quite working as expected for Ubuntu.

[mikee47]

Yep, turning build debugging on it's using relative paths when restoring the cache. Looks like the cache for IDF was saved in Windows and ended up being restored to a sub-folder somewhere. I'll have a dig about and see if the damn thing can use absolute paths like it's been given.

[mikee47]

Hang on, what's varibale ? I thought AI could spell...