[MM-47081] Migrated "components/searcheable_channel_list_test.jsx" to TypeScript (#23886)

* Converted searcheable_list_test to TypeScript

* Reverted mock data for channels props. Resolved minor formatting issues

* Updated snapshot for searcheable_channel_list test file

* Removed obsolete snapshot of searchable_channel_list.test.jsx as searchable_channel_list.test has been converted to TypeScript

webapp/channels/src/components/searchable_channel_list.test.tsx

@@ -18,6 +18,7 @@ describe('components/SearchableChannelList', () => {
         toggleArchivedChannels: jest.fn(),
         closeModal: jest.fn(),
         hideJoinedChannelsPreference: jest.fn(),
+        myChannelMemberships: {},
         shouldShowArchivedChannels: false,
         canShowArchivedChannels: false,
         rememberHideJoinedChannelsChecked: false,