Client Strict Version Checking

[Meltie2013]

This will need some decent testing to make sure we can login valid clients (e.g untouched clients) as the day you downloaded it to play on the official servers.

Original Commit from TrinityCore: TrinityCore/TrinityCore@250fcc8

Changes Made:

• Implement version checking for clients to make sure they are not modified. (e.g. signature wise and/or hacked)

How to Test:

• Enable the version checking in the realmd.conf and attempt to login. If you make it past the login screen, your client is valid.
  If not, you'll be greeted with a version error message.

Disclaimer:

• Not every client version has a seed to verify if the client is valid or not. Please keep that in mind.

Testing Changes:

• If you like to test these changes before directly merging these into master branches, input these commands down below.

git fetch origin pull/14/head:strict_version_checking
git checkout strict_version_checking

Note: Feed back is needed and possible changes.

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This change is 

[billy1arm]

https://github.com/mangoszero/server/blob/master/cmake/MangosParams.cmake#L4

Will need to be changed when this is pushed to flag that there are new settings in the .conf file

[billy1arm]

@Meltie2013 - Somehow i'd completely missed this PR. Did you ever get any feedback at all ?

[Meltie2013]

@billy1arm I completely forgot about this PR 😆