Catch "#ifdef T8_ENABLE_*" in files before commit

[holke]

Feature request

Add a script that checks files with content "#ifdef T8_ENABLE_*" and prevent them from being committed.

Is your feature request related to a problem? Please describe.

See #1370
We noticed that we often use "#ifdef" but should be using "#if".
To prevent further missusage these errors should be caught early.

Describe the solution or feature you'd like

A script that given an input file checks for the strings
"#ifdef T8_ENABLE_*" (OCC/VTK/DEBUG) and returns error when found.
Call this script inside the commit hook for each file.
Abort the commit if string was found.

Describe alternatives you've considered
None

Estimated priority

"Priority: medium"

Additional context
None