Description of the new feature/enhancement

Windows Terminal doesn't appear to support the dim ansi escape code (SGR 2) or italic (SGR 3). Adding support for these would I think bring WT up to feature parity with most OSX and Linux terminals.

There are other SGR escape codes that would be nice to have, but aren't as common or as useful as dim and italic.

Proposed technical implementation details (optional)

Dim strikes me as an easy one to achieve. I imagine italic would be a little trickier.