Hi, 

Currently I'm using okular as my main pdf reader for academic philosophy papers and books (PDF files). I often use the annotation feature to make notes while reading through a document. However, when I read books the list of annotations soon becomes long and it becomes difficult to find particular notes when I want to use them while writing or when I want review them.

Okular's review panel does have search function but currently it only seems possible to search for annotations of a particular type and it doesn't allow a user to searche the contents of those annotations. So I would like to request the following feature: That the search function in the review panel is enhanced so that it can also be used to search the contents of the popup notes. For me personally that would this feature even more useful than it currently is.

Just to give another example why this would be useful. I'm currently reading through a scanned e-book which only has embedded image content. So there I use the 'Blue Polygon' feature to highlight the interesting parts and double-click those areas to enter my remarks about that passage in the popup note. The review panel (with 'group by page' and 'group by author' both turned off) just gives a list of notes with the title line. In order to find a particular note I had previously written and of which I vaguely remember the content, I can now only use the tooltips that are displayed when I hover over the individual notes to find these notes back. But if you have a long list of annotations that does take a lot of time. So therefore an automatic search function would be useful.

Reproducible: Always

Steps to Reproduce:
1. Have a document with many annotations
2. Enter a keyword in the review panel's search field that you are sure of that it is in one of the popup notes (let's take the name Ihde as an example)
3. No results are returned (unless the keyword corresponds to a particular annotation type such as "Line"
Actual Results:  
The search function does not return a list of annotations that contain the name Ihde.

Expected Results:  
A list of annotations containing the name Ihde.