Add fields for changing Contrail database TTL in plugin UI.

Provide the ability to change parameters Database TTL for Deployment engineer.
Depending on the volume of disk space and drive type (HDD / SSD), we can change Analytics TTL parameters.
Analytics data is written to a database in Contrail. The data expires after the default time-to-live (TTL) period of 48 hours.
Cassandra database allows to specify a TTL (time to live) for all the data written to the database. After the TTL, that data expires and is no longer available for queries.

Contrail plugin has the following TTL parameters in config file /etc/contrail/contrail-collector.conf configured:
analytics_data_ttl=48
analytics_config_audit_ttl=2160
analytics_statistics_ttl=24
analytics_flow_ttl=2
In config file /etc/contrail/contrail-analytics-api.conf
analytics_data_ttl=48
analytics_config_audit_ttl=-1
analytics_statistics_ttl=-1
analytics_flow_ttl=-1