Add relation filter in advanced search

[cpita-work]

Describe feature

Currently:

• The "search string" field doesn't allow for notes, just text, so you have to type something like ~template.title = ....
• The "ancestor" field is only for ancestors and moreover for a single ancestor.

This makes searching for relations cumbersome and unintuitive. For example I would like to get all my books (a template) that have certain topic (an ancestor). Or all my tasks (an ancestor) that belong to certain project (another ancestor). These are things that Trilium excels at representing, not so much at surfacing.

Two possible solutions:

• Turn the "ancestor" field into a "relation" field with multi selection.
• Remove the ancestor field altogether and add both label/relation autocompletion and @-style autocompletion to "search string".

Additional Information

No response

[cpita-work]

Related to the above, Quick Search should also index relation titles (or their entire paths), so that say "book tristram" is a useful query when book is represented as a template. As a workaround one can set #book as a label in the template, but this is a duplication of structure that shouldn't be required.