Improve Add-A-Technique UX

[MarkDavidson]

As a user, I want to more easily add techniques to a sentence, so that I can create higher quality mappings.

Acceptance Criteria:

• In the Add-A-Technique modal (pictured below):
• Use the naming format: "<Tactic>: <Name> (TID)"
• Sort Tactics and Techniques how they are sorted in ATT&CK (Tactic -> Technique -> Subtechnique)
• Add a search widget that supports typing in the name and autocompleting it

[MarkDavidson]

Estimated at 5 points largely because Tactic is not stored in the database and that is a larger problem to solve than just UX treatment.

[emmanvg]

The search widget was added in the linked pull request.