Allow string for cpuFrequency and swoFrequency

[mm-mm-bb]

I need to support different chip with clock speed. The setup is:

• in the CMakePresets.json, each preset define a cacheVariables with the desired clock speed
• cmake will save that variables inside of the .vscode/settings.json
• in the launch.json i assign the variable to the "swoConfig.cpuFrequency"

Unfortunately, while this work for stuff like the swoPort, on the cpuFrequency field i get error "Expected "number"."

Describe the solution you'd like Allow cpuFrequency and swoFrequency (but really any numeric field) to be a string. Something similar was implemented here: https://github.com/microsoft/vscode-js-debug/pull/1880/files

Describe alternatives you've considered CMake would have to edit the launch.json and not only the setting.json. (launch.json using cacheVariables directly would NOT fix, as seems ${} must be in quotes to work)