[connectors] Content node retrieval functions for Zendesk (#8216)

* refactor: remove unused function

* feat: implement retrieveContentNodeParents

* feat: implement the batch content node retrieval

* refactor: replace then with awaits

* feat: use the new permission system for batch node retrieval

* feat: set Help Centers and Tickets to be folders instead of databases

* refactor: define a generic method to identify the type of an internal ID in batch/parent retrieval and permissions setting

* refactor: use the generic getIdFromInternalId when retrieving help center permissions

* refactor: use the generic getIdFromInternalId when retrieving tickets permissions

* refactor: prevent get...IdFromInternalId functions from being exported

* refactor: use the generic getIdFromInternalId when retrieving help center permissions

* refactor: use the generic getIdFromInternalId when retrieving tickets permissions

* refactor: add a method toContentNode for the ZendeskArticleResource

* perf: replace a Promise.all of 3 requests with a single one + filters

* refactor: add methods getHelpCenterContentNode and getTicketsContentNode to centralize the content node definition in zendesk_resources.ts

* fix: remove an obsolete catch

* refactor: add a method toContentNode for the ZendeskTicketResource

* fix: remove an unused import

* refactor: use the toContentNode methods in retrieveSelectedNodes

* refactor: regroup the permission retrieval functions into one that handles all cases

* update connectors/src/connectors/zendesk/lib/permissions.ts

Co-authored-by: Thomas Draier <[email protected]>

* feat: throw errors on unrecognized internal IDs

* refactor: add assertNevers on id types and handle missing cases

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Co-authored-by: Thomas Draier <[email protected]>