Proposal: merge all jitutils tools to a single dotnet CLI app

Currently, we have the following tools built in jitutils:

- cijobs
- jit-analyze
- jit-dasm
- jit-dasm-pmi
- jit-decisions-analyze
- jit-diff
- jit-format
- pmi

jit-diff itself has 4 sub-commands: diff, list, install, uninstall.

Would it make sense to merge some or all of these into a single tool, perhaps called something simple like just "jit"?

The build might be simpler and faster, and usage might be easier.

E.g., instead of "jit-analyze" you use "jit analyze": the only usage difference is replacing the dash with a space.

jit-diff, which already has sub-commands, might have its sub-commands elevated to top-level, and the existing "diff" sub-command becoming top-level, which would simplify usage as you would have `jit diff` instead of `jit-diff diff`.

Perhaps this would make the source code sharing and code management a little simpler.

(@echesakovMSFT suggested this idea)