Split apart InstallerFramework into submodules

[j-selby]

The current installer framework module has gotten large and untidy, and is making editing individual components of the application unwieldy.

Proposed solution is to split this into submodules, each perhaps with its own read/write locks depending on needs to break this apart.

This would look something like:

struct InstallerFramework {
    config: Config,
    installer: InstallOps
}