Add Russian translation

[DavidKinder]

Add Russian translation, based on translated .rc file from Nikita Tseykovets: FrotzRussian_rc.txt

From Nikita:

• Check the correctness of values for the Russian language on line 20 (I was guided by https://docs.microsoft.com/windows/desktop/Intl/language-identifier-constants-and-strings)
• Check the correctness of the encoding on lines 21, 51 and 673 (the standard encoding for the Russian language is windows-1251; may need to change but I'm not sure)
• Check the correctness of language code on line 50 and 672 (I did not understand what it is)
• Check the correctness of language code on line 122 (I did not understand what 1200 means; 0x419 is code of Russian language - https://docs.microsoft.com/windows/desktop/Intl/language-identifier-constants-and-strings)

[DavidKinder]

Fixed by commits f8cc5e0b4c07d810d96f3cf8a99bb9560119f599, 44248b1cc0e000af92f109504b7226cc0ae481a7, f993347367609f0ee8e6f9828d25876976c87194, 02abf5a82a76a47a5896b4f7e297a3c02e6855d6, df8f159d98a2a57f64512a23c86858f3b2150e65, c37775c38308a58479df37a4ed34ddcc08acc76c.