Add basic support for arduino-cli detection

[gibwar]

This adds the most basic of support for the environment created from
downloading the Arduino SDK via the official arduino-cli project.

It fixes two issues encountered with detection:

1. If set(ARDUINO_INSTALL_PATH "$env{LOCALAPPDATA}/Arduino15 is used,
   it will work, however the make system will loudly complain that it is
   unable to read lib/version.txt, however generation will succeed.
2. By default, the cli installation is not detected, so this adds the
   install path hint of the $env{LOCALAPPDATA}/Arduino15 path and adds
   basic detection of arduino-cli.yaml which is created from the cli
   setup process.

The Linux update has been validated using Debian Buser running under
WSL1 and all tools work as far as I can tell, including detection,
build, sizing, and upload.

I do not have a Mac available to test, but I am basing the assumption of
$ENV{HOME}/Library/Arduino15 as the install point since that's in the
package path as well.

Using the tool, running a command like arduino-cli core install arduino:samd
will download the tooling, the core, and set up the environment.

Originally I was detecting arduino-cli.yaml as the marker file but
under a brand new installation on Linux that file did not exist, but
inventory.yaml did.

I was unable to detect any version information of a matching SDK or
arduino-cli version, so the assumption of the file existing was enough
to trigger the new flow.

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Fix registry bug when globbing for sketchbook

The existing code fails on Windows installations as it was checking
HKEY_LOCAL_MACHINE instead of the user defined/customized
HKEY_CURRENT_USER as the Personal registry value only exists in the
user registry.

Additionally, the file command does not seem to resolve the registry
directive, so an additional call to get_filename_component was added
to resolve the directory path.

---

Add support for cli-installed libs without IDE

If a library is installed from the Arduino CLI via arduino-cli lib install <lib> on Windows, the default location for the installed
library is under Documents/Arduino/Libraries/<lib>. When the IDE is
not installed, a preferences file pointing to this location is not
created and is not recognized by the build system.

This attempts to resolve the issue by detecting a missing sketchbook
location and the existance of the _reg_documents variable (resolved
when setting up package paths) by resolving the location and setting the
appropriate ARDUINO_SKETCHBOOK_PATH variable, allowing library
searches to find libraries installed by the CLI.

[gibwar]

Pushed two new commits fixing a bug in the documents directory lookup and added a library lookup fallback for libraries installed by arduino-cli without the IDE installed.