[feature] Verbose logging or some way to see what's happening

[HerringtonDarkholme]

Discussed in #904

^{Originally posted by zephraph February 1, 2024}
When I run sg scan I really have no idea what's happening. I don't know if the rules I want to run are actually being run or what files or actually being checked. It'd be nice to add some default logging to give a little more visibility into what's happen. (I do know about the interactive mode which is incredibly helpful when your rules are actually working 😅)

As an external example, when you run deno fmt in a project and it makes no changes it'll print (as an example) Checked 32 files. If a file is modified, it'll print the path to each file changed before printing the number of checked files.

It would be nice if sg scan printed something like Scanned 32 files for 3 rules. It would be further helpful if there was a verbose or debug flag that printed the rules being ran and the files it was scanning for each. This could even be helpful in the single file scan mode.