Hardcoded EN Strings & PL translation

Hardcodeded strings eliminated:

- Altitude Dlg Box
- "exception_draw_polygon"
- "exception_draw_2_more_polygon_points"
- "exception_draw_1_more_polygon_points"
- "mission_is_too_lengthy"

Pl translations:
- WPs list column description + some minor translation edits
- other corresponding PL translations added ...