feat: dedupe - display difference when --dry-run is enabled

[Blaumaus]

This PR adds functionality to show the difference in what would have been changed if the user had run the dedupe command with the --dry-run flag. At the moment the output is not really useful and doesn't give the user any information other than something like added 2 packages, removed 3 packages, and changed 12 packages in 48s.

This PR changes that:

References

Closes #2687
Closes #4398

[wraithgar]

Wow this has been on a lot of folks' wishlist for years!

[ljharb]

Agreed, this is amazing! is it too much to ask to align the output like a table? i'm not sure if the cli has a pattern for that already

[wraithgar]

doctor token org and profile all use tabular output if you want prior art.

How do we feel about displaying this if the config value long is true also? I'm sure folks would love to see this output on request on the real dedupe.

[ljharb]

I definitely would.

I'd also love to see it on npm install, when long is set :-)

[wraithgar]

Just to clarify, these suggestions can be done in separate PRs, I think having dry-run always do this is fine for a start.

[ritaaktay]

Agreed, this is amazing! is it too much to ask to align the output like a table? i'm not sure if the cli has a pattern for that already

@ljharb @wraithgar

Tried out an implementation of tabular format using the examples in doctor etc.
Let me know what you think!

#7174