Need support for alternative format Bytes values

[pbennett]

PyTeal suports Bytes syntax variants like:

Bytes("base16", "0x052001018008010203040506")

I use this to construct TEAL bytcode that's manipulate for LSIG references inside a contract. I don't see any way to do this in Tealish at the moment.

[pbennett]

#60 might suffice for my use case at least as I use base16 exclusively when I need raw bytes.