add ui for player password support

[cwisniew]

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Identify the Bug or Feature request

resolves #2908
resolves #2913
resolves #2916

Description of the Change

This PR resolves the remaining issues for #2907 adding a UI for maintaining players in the player database. An API for the player database is also part of this PR to enable macro access in the future (it is already in use as part of the UI changes).

Possible Drawbacks

This is potentially going to generate an uptick in support requests when people start using this.

Documentation Notes

I have created a post describing how this feature works/can be used
https://rptools-doc.craigs-stuff.net/blog/player-databases
This is hopefully enough to get people started with the feature and can serve as the basis for a new page on the wiki.

Release Notes

• Added player database which allows per user password or public key authentication

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This change is 

[Phergus]

Reviewed 33 of 33 files at r1, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @cwisniew)

[Phergus]

Reviewed 2 of 2 files at r2, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @cwisniew)