Fix tooltip for mapped tasks (#22994)
Fix tooltip for mapped tasks (#22994)

* Fix tooltip for mapped tasks

* Only show count when it exists

* Handle singular task
apache/airflow,Acehaidrey/incubator-airflow,lyft/incubator-airflow,nathanielvarona/airflow,danielvdende/incubator-airflow,Acehaidrey/incubator-airflow,cfei18/incubator-airflow,danielvdende/incubator-airflow,cfei18/incubator-airflow,apache/airflow,nathanielvarona/airflow,apache/airflow,lyft/incubator-airflow,danielvdende/incubator-airflow,danielvdende/incubator-airflow,Acehaidrey/incubator-airflow,danielvdende/incubator-airflow,Acehaidrey/incubator-airflow,lyft/incubator-airflow,apache/airflow,cfei18/incubator-airflow,Acehaidrey/incubator-airflow,nathanielvarona/airflow,cfei18/incubator-airflow,apache/airflow,cfei18/incubator-airflow,apache/airflow,nathanielvarona/airflow,Acehaidrey/incubator-airflow,nathanielvarona/airflow,nathanielvarona/airflow,lyft/incubator-airflow,danielvdende/incubator-airflow,cfei18/incubator-airflow