Warn for unused panels and pages

Closes #1

See merge request !7

Implement charts panel

See merge request !6

terminals clash with ID terminal, refactor to non terminal

Used for code completion and type safety

Basic refactoring and additional panel

See merge request !5

type guard breaks if interfaces only extend (are not adding new
attributes), therefore the type guard is replaced with it's check

Implement panel size

See merge request !4

Implement sidebar and pages

See merge request !3

Add generation for base and stub for panel

See merge request !2

Add react with stub

See merge request !1