Problem: Deleting active plugins can lead to a situation when it is
reinstalled after restart.
Solution: Suggest "delete" code action only for not active plugins.
Whether a plugin is not active is visible by a hint in its header.
Problem: After `vim.pack.update()` it is not clear if plugin is active
or not. This can be useful to detect cases when plugin was removed
from 'init.lua' but there was no `vim.pack.del()`.
Solution: Add ` (not active)` suffix with distinctive highlighting to
header of plugins that are not active.
It will also be shown in in-process LSP document symbols to have quick
reference about which plugins are not active.
Problem: Using `vim.pack.del()` to delete active plugin can lead to
a situation when this plugin is reinstalled after restart. Removing
plugin from 'init.lua' is documented, but can be missed.
Solution: Make `del()` only remove non-active plugins by default and
throw an informative error if there is an active plugin.
Add a way to force delete any plugin by adding `opts.force`. This also
makes `del()` signature be the same as other functions, which is nice.
Problem: There is now way to run `update()` without Internet connection
while there are some workflows that do not require it. Like "switch
plugin version" and "revert latest update".
Solution: Add `opts.offline` to `update()`. This also allows now to
treat `vim.pack.update(nil, { offline = true })` as a way to
interactively explore currently installed plugins.
Problem: `nvim://` scheme feels more like a generalized interface that
may be requested externally, and it acts like CLI args (roughly).
This is how `vscode://` works.
Anything that behaves like an "app" or a "protocol" deserves its own
scheme. For such Nvim-owned things they will be called `nvim-xx://`.
Solution: Use `nvim-pack://confirm#<bufnr>` template for confirmation
buffer name instead of `nvim://pack-confirm#<bufnr>`.
Problem: Confirmation buffer is named with `nvim-pack://` as scheme
prefix and uses buffer id (needed for in-process LSP) as one an entry
in the "hierarchical part".
Solution: Use `nvim://pack-confirm#<buf>` format with a more ubiquitous
`nvim://` prefix and buffer id at the end as the optional fragment.
Problem: In some areas plugin's revision is named "state". This might be
confusing for the users.
Solution: Consistently use "revision" to indicate "plugin's state on
disk".
Problem: No way to granularly operate on plugins when inside
confirmation buffer.
Solution: Implement code actions for in-process LSP that act on "plugin
at cursor":
- Update (if has updates).
- Skip updating (if has updates).
- Delete.
Activate via default `gra` or `vim.lsp.buf.code_action()`.
