Replace lexer switch/case and function calls with lookup tables

This was done together with the first semi-manual pass & check  based on MySQLLexer.g4 grammar
from https://github.com/mysql/mysql-workbench/blob/8.0.38/library/parsers/grammars/MySQLLexer.g4.

It also cuts the size of the lexer from 9460 LOC to 3827 LOC, and the correctness improvements
further reduce the number of failing tests.

Author: JanJakes