Word sequences query builder creates wrong metadata queries

[thomaskrause]

Describe the bug
A clear and concise description of what the bug is.

To Reproduce

Steps to reproduce the behavior:

1. Go to e.g. the GUM corpus
2. Click on the Query Builder button and select the "Word sequences and meta information" query builder
3. Add a metadata box and generate the query
4. A not supported & meta::something term is added

Expected behavior
The new @* operator should be used to create queries for metadata nodes
Desktop (please complete the following information):

• ANNIS Version 4.5.2