The new module replaces dub.internal.vibecompat.core.log by using the
same function names, but implementing colored output and the left
fixed-width tag. Overloaded functions are provided to output colored
text.

Still missing initLogging() and non-TTY stdout/stderr detection

- still keep retrying primary package supplier

- scope (failure) did swallow fatal errors
- improve logging of failures and successes
- rethrow failure of default registry instead of from the last one
- remove failing package suppliers, so we don't keep beating dead horses

Note that some retry logic is already done interally by package suppliers,
so a failing one is unlikely to recover on the next usage.