Task Provider for Cmake build tasks

[elahehrashedi]

feature-request fix: #1656
the defined task:

{
	"label": "CMake: cmake example",
	"type": "cmake",
	"command": "build",
	"group": "build",
	"problemMatcher": "$msCompile",
	"detail": "user defined"
}

Invoke : "Task: Run build Task" and choose the CMake: cmake example task:

a build finished with error (target is chosen from the user defined target)

a build finished successfully (here the project was not configured yet and the target is set to all by default)

and this is a successful build after changing target:

[bobbrow]

util.resolveVariables

I see you copied this over from cpptools. cmake-tools has it's own resolver. Look at expand.expandStringHelper. To supply the opts, do a FindAllReferences and see what the other functions are doing. There may be a way to make this better in the future (e.g. pass in a driver or extension object and we'll fill it out for you), but that would be for a separate PR.

[elahehrashedi]

in future we can use expandStringHelper(str, this.cmakeDriver.expansionOptions) to resolve variables other than cwd.

currently vscode resolves cwd in resolveTask.

[hwmaier]

I just saw this new feature being available in 1.8.0, great addition. It would be nice also to be able to set the "target" in the task definition.

[bobbrow]

We talked about this and kept it "out of scope" for this PR, but I don't think an issue was opened to track it. Thank you for the suggestion. We'll open an issue now.

[bobbrow]

#2122