MM-43144: Add teams loader (#19960)

```release-note
NONE
```

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

store/storetest/mocks/TeamStore.go

@@ -374,6 +374,29 @@ func (_m *TeamStore) GetCommonTeamIDsForTwoUsers(userID string, otherUserID stri
 	return r0, r1
 }
 
+// GetMany provides a mock function with given fields: ids
+func (_m *TeamStore) GetMany(ids []string) ([]*model.Team, error) {
+	ret := _m.Called(ids)
+
+	var r0 []*model.Team
+	if rf, ok := ret.Get(0).(func([]string) []*model.Team); ok {
+		r0 = rf(ids)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).([]*model.Team)
+		}
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func([]string) error); ok {
+		r1 = rf(ids)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
 // GetMember provides a mock function with given fields: ctx, teamID, userID
 func (_m *TeamStore) GetMember(ctx context.Context, teamID string, userID string) (*model.TeamMember, error) {
 	ret := _m.Called(ctx, teamID, userID)

store/storetest/team_store.go

@@ -31,6 +31,7 @@ func TestTeamStore(t *testing.T, ss store.Store) {
 	t.Run("Save", func(t *testing.T) { testTeamStoreSave(t, ss) })
 	t.Run("Update", func(t *testing.T) { testTeamStoreUpdate(t, ss) })
 	t.Run("Get", func(t *testing.T) { testTeamStoreGet(t, ss) })
+	t.Run("GetMany", func(t *testing.T) { testTeamStoreGetMany(t, ss) })
 	t.Run("GetByName", func(t *testing.T) { testTeamStoreGetByName(t, ss) })
 	t.Run("GetByNames", func(t *testing.T) { testTeamStoreGetByNames(t, ss) })
 	t.Run("SearchAll", func(t *testing.T) { testTeamStoreSearchAll(t, ss) })
@@ -132,6 +133,37 @@ func testTeamStoreGet(t *testing.T, ss store.Store) {
 	require.Error(t, err, "Missing id should have failed")
 }
 
+func testTeamStoreGetMany(t *testing.T, ss store.Store) {
+	o1, err := ss.Team().Save(&model.Team{
+		DisplayName: "DisplayName",
+		Name:        NewTestId(),
+		Email:       MakeEmail(),
+		Type:        model.TeamOpen,
+	})
+	require.NoError(t, err)
+
+	o2, err := ss.Team().Save(&model.Team{
+		DisplayName: "DisplayName2",
+		Name:        NewTestId(),
+		Email:       MakeEmail(),
+		Type:        model.TeamOpen,
+	})
+	require.NoError(t, err)
+
+	res, err := ss.Team().GetMany([]string{o1.Id, o2.Id})
+	require.NoError(t, err)
+	assert.Len(t, res, 2)
+
+	res, err = ss.Team().GetMany([]string{o1.Id, "notexists"})
+	require.NoError(t, err)
+	assert.Len(t, res, 1)
+
+	_, err = ss.Team().GetMany([]string{"whereisit", "notexists"})
+	require.Error(t, err)
+	var nfErr *store.ErrNotFound
+	assert.True(t, errors.As(err, &nfErr))
+}
+
 func testTeamStoreGetByNames(t *testing.T, ss store.Store) {
 	o1 := model.Team{}
 	o1.DisplayName = "DisplayName"