feature: Add config button to disable extension

[danimtb]

Added a new entry in the conan extension global configuration to disable it:

• Removes Conan command of prebuild step.
• Removes conandeps from property sheets.

Improved management of configs to use conan from system or from path, enabling or disabling the elements of the window.

• Added a explanation text in search box when extension is disabled to guide the user to enable it and configure the path to the conan client