Change formalized and multi line comment syntax

[smedilol]

Describe the bug
The current syntax for formalized and multi line comment are in conflicts with some of our legacy code.

To Reproduce
(Type)Cobol code that cause the bug : (if any)
For multi-line comment, current syntax is:

*<<

*>>

For formalized comment, current syntax is:

*<<<

*>>>

Expected behavior
To avoid any conflict with our legacy, we'll now use a special character in column 7 to detect a formalized or multi line comment marker.

For multi-line comment, new syntax will be:

%<<

%>>

For formalized comment, new syntax will be:

%<<<

%>>>