Refactor usage of unwrap in re_db, re_format_arrow & re_log_types

[Artxiom]

What

Part of #6330
Removes or explicitly allows unwrap() where it makes sense.

Affected crates: re_entity_db, re_format_arrow, and re_log_types

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[emilk]

Thanks!

[emilk]

there are some CI failures

[Artxiom]

there are some CI failures

I had something similar in my previous PR #6337. Can you check in with @Wumpf? he mentioned that this is probably some issue withe the contributor ci.

[Wumpf]

@Artxiom the one on should be fixed by now but that's also not what was hit here

[Artxiom]

@Artxiom the one on should be fixed by now but that's also not what was hit here

Aaargh...you are right, I'm sorry - I overlooked smthg. Will fix it now.