Dropbox is updating their OAuth2 authentication to issue short-term
tokens, which are already supported by core\oauth2\client.
This commit updates the dropbox repository to use the
core\oauth2 API, which has built-in support for tokens and
offline access.
- Update fetch_dropbox_data to allow different result nodes and version
- Update search to the new URL with new params
- Update the get entities function to account for the change in structure.
There are various places where it's not guaranteed that the
variable being used is array, and instead, can be null, bool, int...
We need to check that because php74 warns about it.
Where possible we have used the coalesce operator as
replacement for isset() ternary operations.
