network-manager: move connection generation to a lib file
    
    Move the connection generation code to a library file so that it can
    be reused from other places.
    
    (cherry picked from commit 6e1e87cd2567801b10b2b4f716436c48688408bf)
    
    Resolves: #1847518
    
    patch_name: 0087.patch
    present_in_specfile: true
    location_in_specfile: 87
    squash_commits: true