Separate terminal version and Windows version in issue template

[zadjii-msft]

We're getting a LOT of issues that are all "I cant read set the terminal as the default terminal" that would all be instantaneously diagnosable if we knew OP's terminal version. Weirdly, these posts always include the OS version. So I'm separating these out into two different line items.

I'm not marking them both as required, because for conhost bugs the Terminal version isn't relevant. I'm debating that with myself.

I might instead go for:

- type: input
  attributes:
    label: Windows Terminal version
    placeholder: "1.7.3651.0"
    description: |
      You can find the version in the about dialog, or by running `wt -v` at the commandline. If your bug doesn't involve the Windows Terminal (i.e. it's a conhost bug), then you can just put N/A
  validations:
    required: true

- type: input
  attributes:
    label: Windows build number
    placeholder: "10.0.19042.0"
    description: |
      Please run `ver` or `[Environment]::OSVersion`.
  validations:
    required: true

[lhecker]

For less technical folks it might help to clarify that these need to be run on the commandline.