Address part of #11: Fully embrace RFC 8949 encoding indicator syntax

[cabo]

• Remove spurious spaces in front of them
• Allow them behind all strings and numbers
• Allow then right after the tag number
• Add embedded to the bstr choice (So now also allow them in streamstring)

Encoding Indicator within streamstring addressed in commit below. With app-string in the picture, there no longer is a syntactic way to check that the chunks of streamstrings are all text or all bytes.