Call list_latest only when needed

[timroes]

The FE code at the moment calls whenever we want the source (or destination) definitions the /v1/source_definitions/list_latest as well as the /v1/source_definitions/list API (see https://github.com/airbytehq/airbyte/blob/master/airbyte-webapp/src/services/connector/SourceDefinitionService.ts#L40).

We only use the values from the later API to figure out the latest docker version of the connector to know if it has an update available. We need that information barely in any place - as far as I can tell only the connector update settings page and only in OSS.

Given that the list_latest APIs return rather large JSON (sources' list_latest is at 2.3MB at the moment at cloud), we should not call list_latest every time we want connector specifications, but instead pull that logic into a separate method/hook that will only be called if we actually need to have that information because we care about updating/outdated connectors.

[octavia-squidington-iv]

cc @airbytehq/frontend

[krishnaglick]

This and this ticket should address this, as well as the followup FE work.

[krishnaglick]

Excessive calls should be gone!