feat/github-cli: support Alpine based images

[Mark S. (the-wondersmith)]

PR adds support for using the github-cli feature with Alpine based images.

Note

PR technically implements an extensible pattern for implementing support for other currently unsupported linux flavors. That's more of a side effect / happy accident than actual intention. That said, if the devcontainers/features maintainers don't have objections, I will happily extend it to the other single-distro (read: debian) features if this PR is accepted. 😅

[Mark S. (the-wondersmith)]

@microsoft-github-policy-service agree

[Mark S. (the-wondersmith)]

As noted in the PR description, if this is accepted I'm happy to tackle:

• python feature not compatible with alpine - better error message #498
• DinD and DoutD does not support Alpine Base Images #751
• PowerShell Feature - Support for Alpine #890
• Git Feature - Add OS support for Alpine #824

and generally adding Alpine support across the board (incrementally).