Allow easy use of other Shipyard providers without accessing Settings.

[Athanasius]

This idea comes from https://github.com/EDCD/EDMarketConnector/discussions/1031 .

The simplest implementation is going to be the " (alt)" text / extra hyperlink.

I quite like the idea of holding ALT causing the 'other' provider to be used, if that's actually possible easily with tkinter.

Tapping ALT during mouse-over to toggle the provider also has merits, and then requires some indication of the currently active one.

[Exsomnis78]

It would be really cool if we could use this ALT menu feature for all hyperlinks (systems and stations, EDSM vs INARA etc.)

[A-UNDERSCORE-D]

Related discussion: https://github.com/EDCD/EDMarketConnector/discussions/1031

[Rixxan]

Closing in favor of #1173