fix: crashes from delimiter matching (#2725)

The feature that selects and highlight's matching delimiters stores the
line and column for the match. If you delete the matching delimiter
while the highlighting is on, then the code was trying to access a
non-existent line causing an exception. Fixed a bug that didn't assign
the right colors when a custom types, a global placed variable and a
member of that custom type shared the same name. Some names were
changed. Some other code was optimized.