Package a Czech voice for Rhvoice

[vojtapolasek]

After the #41 is completed, it would be nice to have Czech voice for the Rhvoic synthesis packaged.
Here are some hints provided by @tyrylu .

First, we need to install the contents of https://github.com/RHVoice/Czech/releases/download/v1.2/RHVoice-language-Czech-v1.2.zip to %{_datadir}/RHVoice/languages/Czech,

and then, we can install contents of https://github.com/RHVoice/zdenek-cze/releases/download/v4.3/RHVoice-voice-Czech-Zdenek-v4.3.zip to %{_datadir}/RHVoice/voices/zdenek-cze.

Note that as there's no install script, the package will have to do all the things manually, likely using the install command in %build, but it should not be so hard, I hope.

[tyrylu]

Note that 1.2 is (as of few days ago) not the latest version of the voice and language data.