Proposal - remove PAC files from repo (and thus tarball/zipball of actions) and install via nuget

[tehcrashxor]

Github's autogenerated "Set up job" step seems to be flakey, specifically for jobs containing our actions here. It usually succeeds, but when it does not, it fails due to timeouts downloading the Action's tarball/zipball corresponding to the selected commitish.

If we do not get a resolution from the GitHub side, our only real option is to reduce the size of the tarball/zipball by removing the largest chunk of it -- the PAC CLI executable and ancillaries.

This PR

1. removes the Windows and Linux copies of PAC from the dist folder,
2. adds a new action actions-install to install the net48 version of PAC from nuget for Windows hosts or net6.0 dotnet tool version of PAC for Linux hosts, and
3. adds checks to throw errors if an action runs which requires pac when the actions-install step has not yet been run.

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This would be a BREAKING CHANGE as no current jobs contain the not-yet-existant actions-install action, and thus we should have a major version change to signify that.

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Example of a job running actions-install followed by Who Am I:

Example of a job which runs actions-install more than once:

Example of a job failing to run who-am-i, as it did not run actions-install first:

[petrochuk]

Are you planning to add Nuget package version to be able to customize packageVersion for new install action? Maybe be default to latest and let customers override it

[tehcrashxor]

Are you planning to add Nuget package version to be able to customize packageVersion for new install action? Maybe be default to latest and let customers override it

Yep, added an override argument.