Port coverage API into v3 part1

This changeset only copies the v2 files into the appropriate v3
directories unchanged. The copy as-is will not be loaded by either
the v2 or v3 extension loaders. The second changeset will then
make the changes required for it to work as a v3 extension.

This is being tried in order to make reviewing of extension
porting easier as gerrit will display only what is actually
changed for v3 rather than entirely new files.

Partially implements bp v3-api-extension-versioning

Change-Id: I50ba45357378311d7bccb71f851e9e2915fc763b
Imported Translations from Transifex

Change-Id: I565654bd20d90aceba2b0a5be6467dac9a9fb965
Merge "Imported Translations from Transifex"
Merge "Port coverage API into v3 part1"