Add support for different keyboard layouts

[cghague]

Related https://github.com/tiny-pilot/tinypilot-pro/issues/1383.

TinyPilot works well when the target and client use an en-US or en-GB keyboard layout. We should improve support for other keyboard layouts to offer the same great experience for more users.

The project may involve tasks such as:

• Detecting or setting the client's keyboard layout
• Detecting or setting the target's keyboard layout
• Adjusting the on-screen keyboard to match the selected keyboard layout
• Translating when the client and target use different keyboard layouts
• Pasting characters not present on either selected keyboard layout