[CI] add Warning in name checking functionality if branch conforms to porting naming, but no float counterpart can be found

We used to have the naming convention check for merges to main-pc, but now everything is on main. Currently, no name checking is done and things just silently use the default which is bad. Pipeline should issue a warning if a branch is a porting branch (identified by the *_basop_* naming) and there is no ref counterpart found.

flowchart TD
    A{Branch name looks like porting branch?}
    B(exit 0)
    C(Get flt_ref equivalent branch name)
    D{flt_ref equivalent branch exists?}
    E(print explanation)
    F(exit 123 - allowed failure)
    
    A -->|No| B
    A -->|Yes| C
    C --> D
    D -->|Yes| B
    D -->|No| E
    E --> F