`ucs` in `Agda.fmt` does not work well anymore

[L-TChen]

After the latest ucs package seems to change its behaviour, Unicode characters are no longer mapped to its TeX-equivalent. For example, Greek letters are not mapped so one needs to define these mappings using

\DeclareUnicodeCharacter{03A3}{\ensuremath{\Sigma}}
…

Perhaps Agda.fmt should be updated with all mappings…? Or, is it better to have an external tex package for this purpose?