Make use of --overwrite / -f in tools consistent

[nbiederbeck]

we have -f as "force" in the other tools (including ml tools). But I think we can adress the --overwrite/-f in another PR to make everything consistent (and maybe inside Tool?)

Originally posted by @nbiederbeck in #1767 (comment)

[nbiederbeck]

Additionally, if we could check the output_path.exists() and not self.overwrite for each output file during initialization, that would speed things up. Currently, that check is done during Tool.finish() when calling Component.write().

[kosack]

Sounds good. Should definitely change everything to --overwrite. I dislike --force, since it is not clear what is being forced. Astropy and gammapy also use --overwrite for everything. I don't think there has to be a short name for this, and would even discourage adding one, so no -f or -o, etc.

[nbiederbeck]

What's your opinion on multiple output files?

I assume one --overwrite is enough to overwrite all output files.

[kosack]

Yes, I think so, otherwise it gets quite confusing to have separate options for each.