The tmt library had a bug with ECH with cursor position.
Flesh out the dump_vt to translate the attributes to VT codes
for the buffer to look the same as the attributes indicate.
Ensure the resultant dump has consistently long lines. This
will matter when we start rendering attributes on blanks.
Additionally, simplify the code
significantly taking advantage
of first loop.
C implementation to improve memory and cpu utilization.
Forked off to further move the work off the main process.
Still needs attribute rendition and packaging before merging to main
branch.
