Cleanup ./install_build_tools.sh

[jrcheli]

Right now:

1. there is stuff to support mac that has not been tested in ages. Is it time to remove it?
2. the stuff to build on CentOS 7 (yum package manager) needs work. (See https://github.com/criblio/appscope/pull/547 for specifics of what I know). There are additional issues with CentOS 8. Should we put work into this?
3. @pdugas mentioned that the even for ubuntu, the use of sudo in the script made it unsuitable for configuring our builder container. I'm not positive that I understand the details here, but I think the suggestion included that we could improve the script to check for user privileges and adapt whether sudo is used throughout?
4. When the script is run, there are interactive prompts that require user feedback. This is not ideal. Worth fixing?

[seanvaleo]

We should also add the buildx dependency. See steps here: https://github.com/criblio/appscope/issues/448#issuecomment-1421709475