Add decompress_gzip_field processor (elastic#12733)

This PR adds a new processor named `decompress_gzip_field`. As the name implies, it decompresses gzipped fields.

Example configuration:
```yaml
processors:
- decompress_gzip_field:
    from: "source"
    to: "destination"
    ignore_missing: false
    fail_on_error: true
```

I also added reference configuration to Kinesis functions, so users can quickly enable decoding data from streams.

journalbeat.reference.yml

@@ -270,6 +270,13 @@ setup.template.settings:
 #    target: ""
 #    overwrite_keys: false
 #
+#processors:
+#- decompress_gzip_field:
+#    from: "field1"
+#    to: "field2"
+#    ignore_missing: false
+#    fail_on_error: true
+#
 # The following example copies the value of message to message_copied
 #
 #processors: