OpenAPIv3: Code-assist: Custom title properties in JSON Schema

[tfesenko]

Extracted from #291.
We added several custom title properties to the JSON Schema for Swagger v2 in 3b7a120
Check if we need custom titles in OpenAPI v3 and update the Schema generator(#292) accordingly.

[tedepstein]

Adding to current scope, pending clarification: Will our 3.0 content assist and/or validation use these by default, or will we need to (re-)add custom logic for this purpose?

[tfesenko]

We probably won't need custom title properties. The code which calculates human-friendly label does use title if it's available, but the value of $ref is good enough.

• This code is already used by validation
• It's used by prototype for code-assist for Better code completion proposal for name/key of patterned properties and array elements #227

This logic is currently implemented in MultipleSwaggerErrorBuilder.getHumanFriendlyText(JsonNode, String), but it will be moved to a more appropriate location when we decided to use it for code-assist too.

I don't see any cases where we need the custom titles. Closing this issue for now. We can always reopen it if needed.