Unicode Keyboard door 8472

The addon provides a simple, keyboard-oriented way to search for and input characters from the raw Unicode Character Database by their official names (such as "SURFACE INTEGRAL"), code blocks (e.g. "Math_Operators") and general character categories ("Sm", i.e. Symbol, Math).

Additionally it can directly substitute a small subset of latex syntax with equivalent unicode character sequences while you type.

Note that this is not a specialized emoji input, while it is easy to enter the basic emoji there currently is no special support for the composite sequences.