fix testml for new bridge
Consolidate and reorganize read() tests

Read tests were scattered and are now in a single .t file.

Moves t/data/51491... to t/tml-local/nesting.tml as it is a parse test,
not an encoding test, so can be a .tml file

Removes t/data files now tested in t/tml-world.  Renamed t/data/one.yaml
to ascii.yaml for clarity of purpose Converts one remaining untested
file into t/tml-local/documents.tml

Also simplifies some of the multibyte/BOM data files to just
the relevant data that might cause problems.