Investigate and track colorized CMake/Build output API dependencies

[sinemakinci1]

Investigate and track colorized CMake/Build output API dependencies

[gcampbell-msft]

Some locations that will help investigate: microsoft/vscode#145234 (comment), microsoft/vscode#209548

[gcampbell-msft]

Update on the API: microsoft/vscode#145234 (comment)

[gcampbell-msft]

Overall, I think that the main two options for solving the colorized CMake build output is the following:

1. Improve the syntax textmate that we provide for the CMake/Build output pane.
   1. This is technically already solved through a workaround mentioned here: #478 (comment). This could be added as a dependency or brought in-box to make it easier.
2. Modify our tasks support (cmake) and our shell integration to use the proposed API here: microsoft/vscode#145234 (comment)
   1. I think that this would include modifying our CustomBuildTaskTerminal class to use the new API.

[gcampbell-msft]

Adding reference #2783

[gcampbell-msft]

Overall, in response to this comment and adding more context: #3683 (comment).

1. I don't think there is work to do for the output pane. If people want colorization for their output pane, they will have to do something external either way because of the Output Channel not supporting colors from VS Code. There are currently workarounds for this that currently work for a decent amount of people.
2. The way that we can provide colorization to users that explicitly want it is through tasks, either manually created by them, or by fixing our tasks support to go through the new Terminal API that is being developed here: microsoft/vscode#145234 (comment)
   1. There is one note to make here, and that is that colorization will happen in the terminal. BUT, there may be additional steps in their CMake project that they need to take either way, in order to get colorization to happen. https://cmake.org/cmake/help/latest/variable/CMAKE_COLOR_DIAGNOSTICS.html, https://stackoverflow.com/questions/9963783/how-can-i-configure-cmake-to-generate-a-buildsystem-that-emits-colored-errors-an, etc.

[gcampbell-msft]

I've done minimal testing and chatting with the maintainers here microsoft/vscode#145234 (comment), and while it's not EXACTLY what we want in terms of a simple async-await pattern for invoking a command and getting the exit code, we can definitely use the API to do what we want. Therefore, this API, once officially supported/released, can be used for our task support and we should be able to provide an officially supported way to route tasks (or build) to a terminal and have colorization (assuming their project is set up for colorization in the terminal).

@sinemakinci1 @microsoft/vscode-cmake FYI.