Bugfix, Canvas and Mindmap content didn´t show in search

[CobriMediaJulien]

Fix for #669

[eliandoran]

@CobriMediaJulien , the search is not perfect but it's a good starting point.

More specifically, it doesn't do a text search but a full content search. In the context of both the mindmap and canvas notes, the content is a JSON, so if you search for the keys inside the JSON they will be found (e.g. try searching for nodeData to get a list of all the mind maps). This can cause false positives when searching for some very generic texts.

@zadam already solved this issue, but for HTML files in note_content_fulltext.ts, look for the preprocessContent method. Most likely we would have to define some kind of filter to only take user data (or at the very least JSON values instead of also keys).

[CobriMediaJulien]

I could implement a filter e.g. :

Canvasfilter:
.elements
| filter(.type == "text")
| pick(.text)

mindmapfilter:
.nodeData
| pick(.topic)

then the only key present to compare in fulltextsearch is text: "some default text". your thougts?