This change primarly adds a new `Open with...` entry to the explorer context menu. To do this however, I had to make a few other changes:

- Add a new explorer context key for availible editors
- Moved the editor select prompt into a new function called `openEditorWith`
- Use `openEditorWith` for the new `open with` explorer command as well as for the `reopen with` command

Fixes #94408

This also adds a `availableEditors` context key that consists of a comma seperated list of editor ids that can be used for `reopen with`

* Add SyncActionDescriptor.from

There are a whole lot of places in our code where have the following pattern:

```
actionRegistry.registerWorkbenchAction(SyncActionDescriptor.create(CreateNewLocalTerminalAction, CreateNewLocalTerminalAction.ID, CreateNewLocalTerminalAction.LABEL));
```

Notice how the class name has to be repeated  three times.

This change introduces a helper function `SyncActionDescriptor.from` that lets you instead just pass in the class:

```js
actionRegistry.registerWorkbenchAction(SyncActionDescriptor.create(CreateNewLocalTerminalAction));
```

* Avoid cast

fixes #84484

For #81574

See #84669 for details of the problem around strict function types. This change converts `SyncActionDescriptor` to use a static `create` function. This allows us to make the `create` function generic so that it can take the correct types for strictFunctionTypes

* wip

* finish

#80959

* add cansavecontextkey

* use save logic for save active editor ctx key

* use context key plus explorer focus

* remove unused imports

* feedback

fixes #80563

fixes #28710

Fixes #75737