settings: resolve configuration settings

[GitMensch]

Is your feature request related to a problem? Please describe.
In my setup there are multiple environments using the same code-workspace (= checked into vcs) and the parts that are different per machine are setup for example in a configuration settings.my.folder (from the machine/user configuration) which I can then use everywhere in tasks by ${config:my.folder} or things like ${env:HOME} "out of the box"; but for extensions this has to be manually resolved as vscode still does not do it directly when calling the api function (microsoft/vscode#2809).

Describe the solution you'd like
Manually search for at least ${config: in at least the file/path related settings like coverage-gutters.coverageBaseDir and resolve it before using the setting, for many people ${env: will be important.

Describe alternatives you've considered
Check out, manually adjust the configuration per local environment, take care to not check in :-(

Additional context
There is a list of official namespaces and variables available, this shows things like ${env:..}, ${workspaceFolder:..}, ${config:..}, ${userhome}.

[ryanluker]

@GitMensch Thanks for submitting an issue!
Definitely seems like a useful addition, and the codebase is pretty setup for doing these changes when the config is initialized. https://github.com/ryanluker/vscode-coverage-gutters/blob/master/src/extension/config.ts

Not sure exactly when someone will get to working on this but I added it into the next milestone 👍🏻.