Use the API to create new tags

[lossitomatossi]

Current Behavior

Currently the only way to create tags is to update an existing project, either through the API or through the UI.

Proposed Behavior

I wish to be able to create new Tags either from /tags or more importantly with a PUT to api/v1/tag. The only info should be name: "name-of-tag".

I was planning to implement a self-service tool outside dependency track where users would be allowed to set up alerts and then letting them choose a tag they wish to be added to that alert, using the "Limit to tags" field. The alert would be created using the API-call after using the API to create a tag.

Now instead the tool will need to verify that a tag exists, (finding a random project the tag should be added to), and then creating an alert and adding the tag to the alert.

Checklist

• I have read and understand the contributing guidelines
• I have checked the existing issues for whether this enhancement was already requested