[MM-14502] Add experimental flag to enable click-to-reply (#10415)

model/config.go

@@ -717,6 +717,7 @@ type ExperimentalSettings struct {
 	ClientSideCertEnable            *bool
 	ClientSideCertCheck             *string
 	DisablePostMetadata             *bool
+	EnableClickToReply              *bool
 	LinkMetadataTimeoutMilliseconds *int64
 	RestrictSystemAdmin             *bool
 }
@@ -734,6 +735,10 @@ func (s *ExperimentalSettings) SetDefaults() {
 		s.DisablePostMetadata = NewBool(false)
 	}
 
+	if s.EnableClickToReply == nil {
+		s.EnableClickToReply = NewBool(false)
+	}
+
 	if s.LinkMetadataTimeoutMilliseconds == nil {
 		s.LinkMetadataTimeoutMilliseconds = NewInt64(EXPERIMENTAL_SETTINGS_DEFAULT_LINK_METADATA_TIMEOUT_MILLISECONDS)
 	}