Part of #8090
Adds the ability to include a group (`--group`) in the sync or _only_
sync a group (`--only-group`). Includes all groups in the resolution,
which will have the same limitations as extras as described in #6981.
There's a great deal of refactoring of the "development" concept into
"groups" behind the scenes that I am continuing to defer here to
minimize the diff.
Additionally, this does not yet resolve interactions with the existing
`dev` group — we'll tackle that separately as well. I probably won't
merge the stack until that design is resolved. The current proposal is
that we'll just "combine' the `dev-dependencies` contents into the `dev`
group.
Part of #8090
Adds the ability to add and remove dependencies from arbitrary groups
using `uv add` and `uv remove`. Does not include resolving with the new
dependencies — tackling that in #8110.
Additionally, this does not yet resolve interactions with the existing
`dev` group — we'll tackle that separately as well. I probably won't
merge the stack until that design is resolved.
Zanie Blue