Begin work on a data request API (#4045)

[Core] Data Deletion And Disclosure APIs

 - Adds a Data Deletion API
   - Deletion comes in a few forms based on who is requesting
   - Deletion must be handled by 3rd party
 - Adds a Data Collection Disclosure Command
   - Provides a dynamically generated statement from 3rd party
   extensions
 - Modifies the always available commands to be cog compatible
   - Also prevents them from being unloaded accidentally

tools/primary_deps.ini

@@ -17,6 +17,7 @@ install_requires =
     discord.py
     distro; sys_platform == "linux"
     fuzzywuzzy
+    markdown
     python-Levenshtein-wheels
     PyYAML
     Red-Lavalink