Updated semantic highlighting (except for constant numeric values).

Organized DTRAMLanguageServer.java

Updated sub-channel keyword to latest one.

Updated main entry point

Removed unnecessary workspace service.

Added keyword tokens support in SemanticAnalyzer

Removed multiline comments support

Implemented basic semantic tokens.

Created test cases for SemanticAnalyzerTest.java

Created semantic analyzer to be able to make tokens of atomic, string and type tokens semantic

Created semantic token based from Token.java

Moved some tokens from Tokens.java to Constants.java, Functions.java and Types.java

Moved comment tokens from Tokens.java to Comments.java

Separate tokens into Tokens.java, Keywords.java and Operators.java

Added package-info.java

Changed method signatures

Optimized some codes in Tokenizer#execute

Optimized some codes in Tokenizer#splitBySpace

Changed the way to split tokens by symbols and fixed known bugs.

Removed some regex constants.

Use String#length instead of String#codePointCount

Updated test declarations.

Tokenizer#splitBySymbol is still buggy.

Added test case for Tokenizer#splitBySpace and Tokenizer#splitBySymbol

Added test case for Tokenizer#splitBySymbol

Changed access modifiers to be able to access methods in Tokenizer.java from TokenizerTest.java

Added test case for Tokenizer#splitBySymbol.

Implemented Tokenizer#splitBySymbols to be able to tokenize by more symbols.

Implemented equals() to test in JUnit 5.

Implemented new constructor and fixed toString() and JavaDoc comments.