Add a unique_id field for identifiying conversations (#914)

* Add a unique_id field to the conversation object

- This helps us keep track of the unique identity of the conversation without expose the internal id
- Create three staged migrations in order to first add the field, then add unique values to pre-fill, and then set the unique constraint. Without this, it tries to initialize all the existing conversations with the same ID.

* Parse and utilize the unique_id field in the query parameters of the front-end view

- Handle the unique_id field when creating a new conversation from the home page
- Parse the id field with a lightweight parameter called v in the chat page
- Share page should not be affected, as it uses the public slug

* Fix suggested card category

src/interface/web/app/components/suggestions/suggestionsData.ts

@@ -408,7 +408,7 @@ export const suggestionsData: Suggestion[] = [
         link: "",
     },
     {
-        type: SuggestionType.Code,
+        type: SuggestionType.Interviewing,
         color: suggestionToColorMap[SuggestionType.Interviewing] || DEFAULT_COLOR,
         description: "Provide tips for writing an effective resume.",
         link: "",