Polish semaphores and indicators

For now, the mod only offers indicators, but semaphores will be added soon.

Here are all the standard indicators included in this mod:
-W1,

-W3,

-W4,

-W5

-W6,W6a and W6b,

-W7,

-W8,

-W9a and W9b,

-W11a, W11b and W11p,

-W12,

-W15,

-W16.

All traction indicators:

-We1a, We1b and We1c,

-We2a, We2b and We2c,

-We3a and We3b,

-We4a, We4b and We4c,

-We8a, We8b and We8c,

-We9a and We9b,

-We10a, We10b, We10c, We10d, We10e, and We10f.

More coming soon