[MM-42739] Insights - Top Channels API Endpoint (#19953)

* [MM-42739] Initial setup for top channels for team

* [MM-42739] Add initial tests

* [MM-42739] Update tests

* [MM-42739] Add top channels for user

* [MM-42739] Fix query

* [MM-42739] Update query

* [MM-42739] Improve query performance

* [MM-42739] Remove rank

* [MM-42739] Fix tests to use new time range today

* [MM-42739] Add tests for top channels for user

* [MM-42739] Add test for pagination

* Remove top channels by time struct

* [MM-42739] Update test names

* [MM-42739] Remove rank from top reactions

* [MM-42739] Return empty array instead of nil when result is empty

* [MM-42739] Add additional tests and update permissions check for teams

* [MM-42739] Add excluded channel tests for top reactions

* [MM-42739] Move insights to api4/insights and keep time range as string until required

* [MM-42739] Update queries only check DeleteAt after union

* [MM-42739] Improve query performance by using publicchannels table

* [MM-42739] Fix broken query after merge

web/context.go

@@ -374,17 +374,6 @@ func (c *Context) RequireTimestamp() *Context {
 	return c
 }
 
-func (c *Context) RequireTimeRange() *Context {
-	if c.Err != nil {
-		return c
-	}
-
-	if c.Params.TimeRange == 0 {
-		c.SetInvalidURLParam("time_range")
-	}
-	return c
-}
-
 func (c *Context) RequireChannelId() *Context {
 	if c.Err != nil {
 		return c