Investigate using pre-installed func core tools rather than downloading to user home dir

[Timothyw0]

Is your feature request related to a problem? Please describe.
Downloading the func core tools binary is bloating user disk space under $HOME/.swa/core-tools/$FUNC_VERSION

Describe the solution you'd like
In the scenario where it is already installed, we should check if core tools is already available on the user's machine and use that rather than downloading to the home directory

Describe alternatives you've considered
We can also consider using the minified releases of core tools which will take up less space in the user's home dir

Additional context
Changes should be made in this file: https://github.com/Azure/static-web-apps-cli/blob/main/src/core/func-core-tools.ts