Support for `title`/`alias` on `ObsidianSearch`

### 🚀 The feature, motivation and pitch

IMHO, using `ObsidianSearch` grepping is sub optimal when you already known `title` or `alias` (defined on front matter) you are looking for.

In addiction, `ObsidianQuickSwitch` is not useful when notes are named after `ID`s.

### Alternatives

_No response_

### Additional context

_No response_

Start by tracing the ObsidianSearch and ObsidianQuickSwitch entry points and how notes and their front matter are currently discovered. Define completion as allowing searches and quick switching by front-matter title or alias, including notes whose filenames are IDs; the issue does not identify specific files or tests.

Written by the indexing model from the issue text.