Add search to asdftool

[braingram]

Converted to an issue to add a milestone.

Discussed in #1838

^{Originally posted by tddesjardins September 23, 2024}
It may be useful for users if the search functionality were added to asdftool. I know the search option exists inside python, but a CLI option may be useful as well. Grep seems to work alright, but does put a lot of spam into the terminal about binary blocks.