Removes need for matching begin-end scope names

[gnikit]

Removes need for matching begin-end scope names

Previously nested scopes had to be closed in the reverse order than they
were opened e.g.

subroutine scope_1()
    subroutine scope_2()
    subroutine scope_3()
    end subroutine scope_3
    end subroutine scope_2
end subroutine scope_1

However with preprocessor conditionals that would be an issue since

subroutine scope_1()
#ifdef DEF
    subroutine scope_2()
#else
    subroutine scope_3()
#endif

#ifdef DEF
    end subroutine scope_2()
#else
    end subroutine scope_3()
#endif
end subroutine scope_1

scope_2 and scope_3 would be in the same level on the AST, so it is
no longer valid to expect scope_3 to close before scope_2.

The solution to this is removing the strict requirement for scopes to
have matching begin-end names from the regex. The type of scopes
where this requirement is removed are:

• Functions
• Modules
• Programs
• Module Procedures
• Subroutines
• Submodules

Fixes Erroneous syntax highlighting with subroutine names and preprocessor conditionals #278