Introduce a bespoke `global-server.nix` module. This is less DRY, but
much simpler.
The `lsp.servers."*"` options are different enough from the other
`lsp.servers.<name>` options that it is simpler to just declare them
separately.
Now that we have a dedicated `global-server.nix` module, we no longer
need to split the normal server module into `server.nix`+`server-base.nix`
This partially reverts f2e96b67a3
`"*"` is effectively a meta server, where shared config/defaults can be
set.
It shouldn't have options like `activate` or `package` which relate to
"real" servers. Therefore, we'll use `server-base.nix` directly, instead
of the full `server.nix` module.
`config` is a loaded term within modules and options.
`settings` is the name usually used for freeform config in nixvim and
most other module configurations.
Convert the `attrsOf (servers.nix)` option to a freeform submodule.
Declare a `servers.nix` option for each lsp server listed in
`lsp-packages.nix` that has a known nixpkgs package.
This allows users to override the name used for a given `lsp.servers.*`
entry. The default is still the attr-name.
This may be useful to inject raw lua, or to configure the same server in
different ways via different attrs.
