Refactoring of OpenType/TrueType font construction

We are using bytesToString and then using stringToArray just to concatenate multiple chunks of the Open Type file. The patch refactors code to build the file directly in the continuous Uint8Array. Also removing stringToArray since the file builder can accept the strings (not just arrays).
you could push this down into the else which contains the if string/else block to avoid creating the local vars for the Uint8Array case. But it will be quite micro, so if you prefer the current for readability thats fine.