Redesign the mapping structure used in Cairo coverage to decouple from the profiler and include additional required information

[ksew1]

In the current implementation of Cairo coverage, we use mappings in the form of: Sierra ID -> List of Details, where each detail is a triple consisting of:

• Path to file
• Line in file
• Function name

The function name is derived from cairo-profiler, which creates a tight coupling with the profiler; any changes in the profiler can lead to issues in the coverage computation and vice versa. Additionally, the current mappings lack critical information, forcing us to rely on heuristics.

Issues with Current Mappings:

• Tight coupling with cairo-profile.
• Missing information on cfg context for each line.
• Lack of branch coverage mappings.
• Wrong handling of macros (macros shouldn't be present in mappings)
• Undefined start and end lines for functions.

The result of this task should be design doc presenting format of new mappings

Related issues: #29 #27 #30 #33