[Defender] Use IP Geo Block plugin as a guide

When implementing the new IP geo-blocking features in Defender, please use the IP Geo Block plugin as a guide.

The settings for that plugin allow for refinement, and if Defender does not include the same features that I personally would not be using that specific Defender functionality. Examples:
- High level preference to start by blacklisting (followed by whitelist exceptions) or to start with whitelisting (followed by blacklist exceptions).
- Separation of front-end/back-end rules.
- Simple entry of a list of country codes. My list for most sites: "CN,RU,KR,TR,TW,VN,SG,UY,PH,PK,UA,RO". Including XX, YY, ZZ options.
- CIDR and ASN
- Bad signatures (described in my other most recent request for Defender)
- XML-RPC block by country (in addition to simple on/off toggle)
- Detailed logging : I need to be able to see which IPs are hitting specific pages, block by IP/country, filter/remove those logs, and continue to whittle down the log list until all traffic has been evaluated.
- Selection of APIs and local databases to use. Some are better than others and more than one db helps to ensure successful geolocation.

Look at the IP Geo Block Support Q&A to see where that plugin has fallen short.

Consider partnering with the author to share code - collaborate rather than compete.

I request and recommend a pre-release beta of this geolocation feature. I think it's too easy to get this one wrong, and you don't want to do a general release that accidentally blocks legitimate traffic for a lot of your members.

When publishing the release that includes this feature, please simultaneously update the roadmap with the next set of features that are already being considered. This will save a lot of requests here "thanks, but it doesn't do this". (I think this kind of pre-emptive strike would be good for any new release of any plugin that attempts to duplicate functionality found elsewhere.)