Allow `Alphabetic`, `Lowercase`, `Uppercase` and `XDigit` in Java

[Aloso]

Describe the bug

Here's the list of boolean Unicode properties that Pomsky supports. Java only supports some of them: documentation. Still, the supported properties should be allowed in Pomsky:

Alphabetic
Ideographic
Letter
Lowercase
Uppercase
Titlecase
Punctuation
Control
White_Space
Digit
Hex_Digit
Join_Control
Noncharacter_Code_Point
Assigned 

Java uses the Is prefix for boolean properties, e.g. [Alphabetic] should compile to \p{IsAlphabetic}.

Expected behavior

The expression [Alphabetic] [Lowercase] [Uppercase] [Hex_Digit] should successfully compile in Java.