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.

Added maven-surefire-plugin to see test reports in browsers.

Added Position#move method.

Renamed some fields and methods in Token.java.

Made simple test-case for tokenizer.

Implemented model-file tokenizer that has abilities to tokenize comments and splits token by spaces.

Made skeleton of a model-file validator.

Implemented LSP4J to be able to launch basic language server.