Add brew for main packages install from macos

[timur-harin]

@yegor256
In this pull request, I have added:

• Check for macOS system
• Check and installation of brew if not installed
• Install steps using brew in steps/install.sh

[yegor256]

@timur-harin don't you think that installing homebrew to an innocent user's machine is a bit intrusive? :) They clone our repo, run make install and then boom! -- their system has a new system-level component. I think, they will be surprised at best.

[timur-harin]

@yegor256
I agree. So we can make echo message, that if brew not installed you can download it and put install link?

[yegor256]

@timur-harin yes, this will be reasonable. We either 1) use brew install ... if brew is present, or 2) we say "if you install Homebrew, all necessary packages will be installed automatically by make install"

[timur-harin]

@yegor256
I updated this PR:

• Now it will not install brew, only suggest if not found

[yegor256]

@timur-harin thanks!