Support template refresh for tcp transport in exporter

[zyiou]

Is your feature request related to a problem? Please describe.
Currently for logstash netflow codec plugin we are using in elk flow collector in Antrea, there is a cache_ttl field, which will expire the records after certain time. Therefore, the templates for tcp transport will also be removed when expired even though it does not align with IANA standard.
https://www.elastic.co/guide/en/logstash/7.x/plugins-codecs-netflow.html#plugins-codecs-netflow-cache_ttl

Describe the solution you'd like
We already set the expiration time of tcp templates to be very large (365 days) in Antrea antrea-io/antrea#2387. In go-ipfix exporting process, we can add an option for tcp transport to have template refresh just for ELK flow collector to work well.

Describe alternatives you've considered
Since in the future we may move ELK flow collector to Opensearch, we can also take a look at what Opensearch will provide for tcp transport. https://opensearch.org

Additional context
N/A