Motivation
The "empty" first option for "File type" dropdown looks weird, and it is hard for people to understand they need to click there if they want to get rid of a file type specification
MOCK:
Acceptance Criteria
- "Select file type" is the default for the file type field and means that the keyword is currently not used
- "Select file type" is the first entry in the list of file types and can again be selected by the user