[FEAT] add vocabulary annotation

[surchs]

This PR adds a new annotation component (annot-vocabulary.vue) for

• diagnosis
• assessment tools

annotation.
The functionality at the moment is limited to freeform text fields without validation.
For diagnosis, every unique value is displayed and can be mapped to a term. The tooltip suggestions ask for SNOMED-CT.
For assessment tools, every column name labeled as "about assessment" can be mapped to a term, and no unique values are shown.

Closes #63

Known limitations:

• the provided mappings are not (yet) tied to the global app state. So navigating away and back to the annotation page will reset all text fields
• similarly, the mappings (unique value -> vocabulary term, and column Name -> vocabulary term) are not emitted to the parent components. Thus: the data dictionary does not get updated based on these mappings (yet)
• because of the above, annotating assessment tools currently does not affect the app outside of the annotation page (no unique values to update in the data table, and heuristics are not emitted). In a future iteration, we'll want to use the mappings of the annotation columns to update the data dictionary
• there is no validation on the input data (although the code is prepared and commented out). Even for this preliminary version (where we do not actively search vocabularies but just provide text fields), we should validate the input to check that we get valid vocabulary URIs. This is not yet implemented, so any text input is valid at the moment
• there is a lot of code duplication between this component and the ones used for age and sex.