CreateDefinition: Properly parse DEFAULT value.

Fixes phpmyadmin/phpmyadmin#12012.

Signed-off-by: Dan Ungureanu <udan1107@gmail.com>

Condition: Allow keyword INTERVAL.

Expression: Refactored parsing options.

Context: Added custom mode that avoids escaping when possible.

Misc: Add test cases for fixed bugs.

Allow NULL in expressions.

Expressions may begin with a function that is also a reserved keyword.

Fixed a bug where formatter split the function name and the parameter…

…s list.

Updated dependencies.

Fix error message.