[MM-44488] Cloud limits: enforcing messages (#20362)

* Add new Job to keep updating the last_accessible_post time

* Filter out posts for funcs returning PostList model

* Separate methods to get and compute cache

* filter pinned posts

* For posts with sorted CreateAt order, support a faster form of filtering.

* Add inaccessible header for getPost and getPostsByIDs APIs

* replace manual binary search with the std. library

* in-place filter posts

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>
Co-authored-by: Nathaniel Allred <neallred@protonmail.com>

model/job.go

@@ -27,6 +27,7 @@ const (
 	JobTypeCloud                        = "cloud"
 	JobTypeResendInvitationEmail        = "resend_invitation_email"
 	JobTypeExtractContent               = "extract_content"
+	JobTypeLastAccessiblePost           = "last_accessible_post"
 
 	JobStatusPending         = "pending"
 	JobStatusInProgress      = "in_progress"
@@ -55,6 +56,7 @@ var AllJobTypes = [...]string{
 	JobTypeExportDelete,
 	JobTypeCloud,
 	JobTypeExtractContent,
+	JobTypeLastAccessiblePost,
 }
 
 type Job struct {