Tag suggestions on search #2829

Describe the feature you'd like
Show the suggestions, as it is shown when adding tags, when searching. It could be triggered by the character [, opening tag names suggestions and then, after the name, the comparison operator could trigger the dropdown with the values.

Another option is to create new fields where it is possible to select tag name and values to use on the search page side menu.
Something like:

Search by tag:
dropdown do select a tag name || text field for the operator || dropdown for tag value(s) associated to the selected name
new tag search button

Describe the benefits this feature would bring to BookStack users
The point is to be able to easily see what are the current tags configurations and make it more powerful as a tool to bind related content.

Additional context
Please 😄