Build system upgrades

[FallenChromium]

• [x] Read PR documentation
• [ ] Update changelog
• [x] Update documentation

Main changes:

• The default way to manage build dependencies has been changed to Conan (we've used OS package managers before)
• Consuming sc-machine as a library is now much more streamlined: adding it into the CMake tree isn't required anymore
• Some groundwork has been made to make sc-component-manager more flexible

Rationale behind the changes: TBD

TO-DO before merging:

• Depends on #404
• TBD