(GH-143) added buildScript setting

[nils-a]

to configure the build script to be used for "Code Lens" and "Run Task"

fixes #143
fixes #409

This PR makes configuration of the build script for the "Run Task" command and for "Code Lens" possible.
Currently both are fixed to ./build.sh for non-Windows and powershell [...] build.ps1 for Windows.

Using this modification it is possible to have different configurations for the build script using a default value and also using platform-dependent values.

The "current" build script as given in the code would translate to the followin setting of cake.taskRunner.buildScript:

{
  "default": "./build.sh",
  "win32": "powershell -ExecutionPolicy ByPass -File build.ps1"
}

However, if this was to be set in package.json, the setting would always contain a value for win32. Therefore the default for cake.taskRunner.buildScript is null (or not configured) and the runtime-default (of the above given configuration) is set in ExtensionSettings.ts#L72.

One example for an alternate configuration could be:

{
  "default": "dotnet cake",
  "darwin": "./build.sh"
}

using the .NET global tool for all paltforms except OSX/macOS in which case the build.sh would be used.

default is a "required" property and will always be set (see ExtensionSettings.ts#L83) while the other properties of the cake.taskRunner.buildScript object should correspond to one of the values of os.platform().

[gep13]

LGTM!

[gep13]

@nils-a your changes have been merged, thanks for your contribution 👍

[nils-a]

@gep13 I "think" we broke the default setup by removing the --script argument in the code.

Using the default build.ps1 and default settings I get the following output:

❯ powershell -ExecutionPolicy ByPass -File build.ps1 "d:\_dev\test-123\build.cake" --target="Default" --verbosity=normal
Preparing to run build script...
Running build script...
More than one build script specified.
For usage, use parameter --help

I think we need to modify the default settings either to {default: "dotnet cake"} or to

{
  "default": "./build.sh --script",
  "win32": "powershell -ExecutionPolicy ByPass -File build.ps1 -Script"
}