perf: Remove regex dependency to fix per-value recompilation

[fxwiegand]

While profiling our project datavzrd I found that compiling a fresh Regex for every string value causes a lot of overhead. The packer and unpacker both do this in hot loops, so on large inputs the recompilation ends up dominating runtime. Since the patterns only look at a value's first characters, I replaced them with plain string checks and dropped the regex dependency entirely. For us this more than halves the render time on large reports, and shouldn't change the output in any way, right?

[fxwiegand]

@andrewnester thoughts on this?

[andrewnester]

Thank you! Yes, makes total sense

[fxwiegand]

Thank you! Yes, makes total sense

Awesome! Thanks for the quick merge. Also saw you're already preparing the new release so thanks for being so quick with that as well!