Add a reset command to delete all indexed docs and start the crawl+index again

[kyteinsky]

Describe the feature you'd like to request

/

Describe the solution you'd like

A reset command that

1. clears the config values related to the stats
2. clears the queue tables
3. wipes the context chat backend's vector db
4. retriggers the filesystem crawl

Describe alternatives you've considered

The manual way:

1. delete the context_chat php app config
2. delete the context_chat php app
3. unregister the context_chat_backend app with the remove data checkbox checked
4. do the install all over again