[Feature Request]: Support UDFs in the PubsubToRedis template.

### Related Template(s)

pubsub-to-redis

### What feature(s) are you requesting?

The template code extends the JavascriptTextTransformer interface, but doesn't yet implement the UDF support in the templates code:

https://github.com/GoogleCloudPlatform/DataflowTemplates/blob/63091f159e1889e7234988c96a2515498bf9d46e/v2/pubsub-to-redis/src/main/java/com/google/cloud/teleport/v2/templates/PubSubToRedis.java#L133

https://github.com/GoogleCloudPlatform/DataflowTemplates/blob/63091f159e1889e7234988c96a2515498bf9d46e/v1/src/main/java/com/google/cloud/teleport/templates/common/JavascriptTextTransformer.java#L74

We can see how other templates implement UDF support when using this interface and add such support and tests.