MM-52532: Fix golangci warnings (#23709)

https://mattermost.atlassian.net/browse/MM-52532

- Replace golint with revive
- Add makezero linter
- Fix all the required linter failures

Some issues in enterprise and public modules
are yet to be fixed. We send this to expediate things.

server/public/model/version.go

@@ -113,7 +113,7 @@ var versions = []string{
 	"0.5.0",
 }
 
-var CurrentVersion string = versions[0]
+var CurrentVersion = versions[0]
 var BuildNumber string
 var BuildDate string
 var BuildHash string