Incompatible replays can be viewed via 'Summary' screen

[Langbart]

There seems to be a bug with Replay Games screen, in the GIF below I had no mods enabled and wanted to start a replay that required the "Autociv" mod, I couldn't start it by double clicking or using the GUI Start Replay button, but clicking Summary and then Watch Replay it worked.

The bug can be reproduced for A23b, A24b and the current SVN version [25124].

In relation to this problem, Angen also wrote on IRC 0ad-dev (26/mar/21):

[...] also I am not sure if even viewing summary should be possible as mod could remove classes or resources from statistics

[Silier]

In 25268:

Check for replay compatibility when opening summary screen

Summary screen and mainly its statistics can be influenced by mod as much as replay itself with mod removing or adding classes and trackers to the game.
Summary screen allows to replay the match without checking compatibility, that is fine I think if it is prevented to see summary of incompatible replay in a first place.

Therefore this is adding compatibility check for opening summary of replay.

Differential revision: D3799
Fixes: #6119
Tested by: @Langbart