[MM-59361] custom groups & read only channels (#28892)

* added group mention, read only view and post event tracking

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

server/channels/store/storetest/mocks/ChannelStore.go

@@ -2199,6 +2199,62 @@ func (_m *ChannelStore) InvalidatePinnedPostCount(channelID string) {
 	_m.Called(channelID)
 }
 
+// IsChannelReadOnlyScheme provides a mock function with given fields: schemeID
+func (_m *ChannelStore) IsChannelReadOnlyScheme(schemeID string) (bool, error) {
+	ret := _m.Called(schemeID)
+
+	if len(ret) == 0 {
+		panic("no return value specified for IsChannelReadOnlyScheme")
+	}
+
+	var r0 bool
+	var r1 error
+	if rf, ok := ret.Get(0).(func(string) (bool, error)); ok {
+		return rf(schemeID)
+	}
+	if rf, ok := ret.Get(0).(func(string) bool); ok {
+		r0 = rf(schemeID)
+	} else {
+		r0 = ret.Get(0).(bool)
+	}
+
+	if rf, ok := ret.Get(1).(func(string) error); ok {
+		r1 = rf(schemeID)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
+// IsReadOnlyChannel provides a mock function with given fields: channelID
+func (_m *ChannelStore) IsReadOnlyChannel(channelID string) (bool, error) {
+	ret := _m.Called(channelID)
+
+	if len(ret) == 0 {
+		panic("no return value specified for IsReadOnlyChannel")
+	}
+
+	var r0 bool
+	var r1 error
+	if rf, ok := ret.Get(0).(func(string) (bool, error)); ok {
+		return rf(channelID)
+	}
+	if rf, ok := ret.Get(0).(func(string) bool); ok {
+		r0 = rf(channelID)
+	} else {
+		r0 = ret.Get(0).(bool)
+	}
+
+	if rf, ok := ret.Get(1).(func(string) error); ok {
+		r1 = rf(channelID)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
 // MigrateChannelMembers provides a mock function with given fields: fromChannelID, fromUserID
 func (_m *ChannelStore) MigrateChannelMembers(fromChannelID string, fromUserID string) (map[string]string, error) {
 	ret := _m.Called(fromChannelID, fromUserID)