ENV $workspaceFolder is not replaced in clang-tidy settings

[tebartsch]

Using vscode-clang-tidy with the following option

"clang-tidy.buildPath": "${workspaceFolder}/build",

does not work because ${workspaceFolder} is not replaced. Error Log:

Error while trying to load a compilation database:
Could not auto-detect compilation database from directory "${workspaceFolder}/build"
No compilation database found in /home/user/project/${workspaceFolder}/build or any parent directory
fixed-compilation-database: Error while opening fixed database: No such file or directory
json-compilation-database: Error while opening JSON database: No such file or directory