Generate .lcov report

[MaksymilianDemitraszek]

The overview

We should generate .lcov reports using: #9 and #10

The reports shall include:

• line coverage
• function coverage
  We should omit branch coverage at this stage.

Lines in coverage are marked:

• hitable - covered - green 🟢
• hitable - missing - red 🔴
• not hittable - no color ⚪

Reports shall be generated based on cairo vm trace pc's, we should consider a single contract execution for now (only the root of the profiler trace).

Lines states

hitable - covered - green 🟢
Happens when there is a corresponding casm instruction in mappings
and
in cairo vm trace there is a pc pointing to this instruction

hitable - missing - red 🔴
Happens when there is a corresponding casm instruction in mappings
and
in cairo vm trace there is no pc pointing to this instruction

not hittable - no color ⚪
Happens when there is no corresponding casm instruction in mappings, this happens if some code is removed by the compiler, inlined etc.