[ENHANCEMENT] Use ANTLRv4 visitor code to gather suggestions

[jcscottiii]

Is your feature request related to a problem? Please describe. We present as many options for the query box as possible when a user first clicks into it. But some of the terms like group, snapshot and name can be very hard for a user to discover what is going on. In the future, we could easily organize which suggestions to gather by using the generated ANTLR visitor pattern. That generated code provides us with methods we can implement (instead of manually parsing and manually organizing based on term). Given we already use the ANTLR tool chain for the backend, using it again for the frontend should be low effort. Depends on #716

This will help enable the use cases described in #274

Describe the solution you'd like

• An Implemented ANTLR visitor class that gathers suggestions

**Inspired by **

• https://tomassetti.me/code-completion-with-antlr4-c3/
• https://www.abstractsyntaxseed.com/blog/antlr4-autocomplete-library/rules