Fix SCU global namespace conflict in resource_format_text.cpp

[lawnjelly]

FORMAT_VERSION is used in multiple places in the codebase, and #defining it was causing conflicts.

Notes

• I hadn't built master in quite a few days, am surprised no one else was getting this conflict.
• This likely only occurs in SCU build, as other files attempt to add FORMAT_VERSION in enums after resource_format_text.cpp has #defined it.
• Everywhere else seems to more sensibly use FORMAT_VERSION in local enums, which is safer for making sure the correct version is used.
• FORMAT_VERSION_COMPAT and _printerr() weren't causing build errors for me, but seemed worth fixing at the same time.

In general #define should be used with care due to the potential for conflicts with global namespace (and the use of contrived naming may be recommended for defines). This applies not just in SCU builds.

The alternative here would have been to exclude the problematic .cpp from the SCU build in scene/resources/SCsub, but in this case it looks more sensible to fix the unnecessary use of global namespace, which may fix more bugs in the long run.

[akien-mga]

Thanks!