diagnostics: Prefer activating diagnostic under cursor (#52957)

Update the behavior of both `editor: go to diagnostic` and `editor: go
to previous diagnostic` in order to ensure that, if there's a diagnostic
under the user's cursor that isn't active, it is first activated, with a
subsequent call jumping to the next or previous diagnostic,
respectively.

These changes also update how diagnostic activation handles the
situation when the global diagnostic renderer is not registered, as we
used to not update the active diagnostic group in that situation.
However, we now rely on it to determine whether the user's cursor is
already in the active diagnostic, with some tests now failing, so we now
default to an empty set of blocks for the active diagnostic group when
no global renderer is registered.

Release Notes:

- Update both `editor: go to diagnostic` and `editor: go to previous
diagnostic` to prefer activating the diagnostic under the cursor before
jumping to the next or previous diagnostic, respectively

---------

Co-authored-by: dino <dinojoaocosta@gmail.com>

docs/src/reference/all-settings.md

@@ -2098,6 +2098,7 @@ To interpret all `.c` files as C++, files called `MyLockFile` as TOML and files
 ```json [settings]
 {
   "diagnostics": {
+    "button": true,
     "include_warnings": true,
     "inline": {
       "enabled": false
@@ -2106,6 +2107,11 @@ To interpret all `.c` files as C++, files called `MyLockFile` as TOML and files
 }
 ```
 
+**Options**
+
+- `button`: Whether to show the project diagnostics button in the status bar
+- `include_warnings`: Whether to show warnings or not by default
+
 ### Inline Diagnostics
 
 - Description: Whether or not to show diagnostics information inline.