Admin log table (#21153)

* Reformat Log Output for SysAdmin UI

* Restore old code

* Update

* Backend first pass

* PR feedback

* Set helpers to private

* Lint fix

* Fix mocks

* Fix another mock

* Fix lint again

* Fix i18n

* Update app/admin.go

Co-authored-by: Ibrahim Serdar Acikgoz <serdaracikgoz86@gmail.com>

* PR feedback

* FIx lint issue

---------

Co-authored-by: Daniel Schalla <daniel@schalla.me>
Co-authored-by: Nevyana Angelova <nevyangelova@Nevyanas-MacBook-Pro.local>
Co-authored-by: Devin Binnie <devin.binnie@mattermost.com>
Co-authored-by: Devin Binnie <52460000+devinbinnie@users.noreply.github.com>
Co-authored-by: Ibrahim Serdar Acikgoz <serdaracikgoz86@gmail.com>
Co-authored-by: Mattermod <mattermod@users.noreply.github.com>
Co-authored-by: Mattermost Build <build@mattermost.com>

model/system.go

@@ -181,3 +181,15 @@ type AppliedMigration struct {
 	Version int    `json:"version"`
 	Name    string `json:"name"`
 }
+
+type LogFilter struct {
+	ServerNames []string `json:"server_names"`
+	LogLevels   []string `json:"log_levels"`
+	DateFrom    string   `json:"date_from"`
+	DateTo      string   `json:"date_to"`
+}
+
+type LogEntry struct {
+	Timestamp string
+	Level     string
+}