[SPARK-3606] [yarn] Correctly configure AmIpFilter for Yarn HA.

The existing code only considered one of the RMs when running in
Yarn HA mode, so it was possible to get errors if the active RM
was not registered in the filter.

The change makes use of a new API added to Yarn that returns all
proxy addresses, and falls back to the old behavior if the API
is not present. While there, I also made a change to look for the
scheme (http or https) being used by Yarn when building the proxy
URIs.

Since, in the case of multiple RMs, Yarn uses commas as a separator,
it was not possible anymore to use spark.filter.params to propagate
this information (which used commas to delimit different config params).
Instead, I added a new param (spark.filter.jsonParams) which expects
a JSON string containing a map with the config data. I chose not to
add it to the documentation at this point since I don't believe users
will use it directly.

Author: Marcelo Vanzin <vanzin@cloudera.com>

Closes #2469 from vanzin/SPARK-3606 and squashes the following commits:

aeb458a [Marcelo Vanzin] Undelete needed import.
65e400d [Marcelo Vanzin] Remove unused import.
d121883 [Marcelo Vanzin] Use separate config for each param instead of json.
04bc156 [Marcelo Vanzin] Review feedback.
4d4d6b9 [Marcelo Vanzin] [SPARK-3606] [yarn] Correctly configure AmIpFilter for Yarn HA.