Fixup IP logging

[thebeanogamer]

IP logging currently doesn't understand X-Forwarded-For containing multiple values, as happens when using Cloudflare. This fixes that by always using the first value, and includes a migration to clean up old events and use the Database's inbuilt inet type.

This also adds a slightly dodgy manage.py command to view users grouped by IP address. This probably wont be used much, but we have had users ask for it to try and catch cheaters.

You can also now do Member.ips, so that's neat.

[0xAda]

This feature as a whole looks like it could do with a rewrite, but I'm happy to merge this for now

[codecov]

Codecov Report

Merging #272 (da1b0e0) into master (d198ffb) will increase coverage by 0.01%.
The diff coverage is 98.41%.

@@            Coverage Diff             @@
##           master     #272      +/-   ##
==========================================
+ Coverage   96.86%   96.88%   +0.01%     
==========================================
  Files         109      111       +2     
  Lines        5071     5131      +60     
  Branches      274      281       +7     
==========================================
+ Hits         4912     4971      +59     
  Misses        128      128              
- Partials       31       32       +1     

Impacted Files	Coverage Δ
src/ractf/management/commands/group_ips.py	96.15% <96.15%> (ø)
src/member/models.py	100.00% <100.00%> (ø)
src/ractf/tests.py	100.00% <100.00%> (ø)

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