Add more stanza operators (#4312)
Add more stanza operators (#4312)

Of particular importance, are the new operators that will replace the
restructure operator. These include:
- add
- filter
- flatten
- move
- retain

Additionally, this add two new parsers, which may be useful:
- csv
- uri
open-telemetry/opentelemetry-collector-contrib,open-telemetry/opentelemetry-collector-contrib