feat(HIS): add COMF his metric

[AfonsoSantos96]

This PR introduces the feature of checking the comment density within a file.
A file must have a minimum comment density of 0.2.
Two tools are used in this checker. The pmccabe counts the number of statements and the pygount counts the number of comments.
According to the HIS metrics, the comment density is given by the relationship between the number of comments (outside of and within functions) to the number of statements.
So the density is calculated by dividing the total comments (in the file) by the total number of statements (in the file).
As the comments tool also counts the license comments, I have created a variable license_comment_size to remove these comments from the density metric.

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Edited by @danielRep :
To test with https://github.com/bao-project/bao-his-tests just run the command make ci METRIC=comf.

Checklist:

• Tested using the bao-his-tests repo on branch.
• Compared and validated outputs to ECLAIR his metrics assessment on bao-his-tests repo
• I have run the CI checkers before submitting the PR to avoid unnecessary runs of the workflow.

[danielRep]

Updated with the modifications introduced in #68 and changed the output format.

@miguelafsilva5 @josecm
Use the testing repo (https://github.com/bao-project/bao-his-tests) has a dummy testbed for each individual metric verified by the HIS checker.
You only need to clone the repo, checkout the ci to this branch, and then make ci METRIC=comf.

[miguelafsilva5]

I don't know if I'm doing anyhing wrong, but this checker seems to be ignoring inline comments. For example:

    int num1 = 3; /* this doesn't count*/
    int num2 = 4; // this doesn't count

[danielRep]

I don't know if I'm doing anyhing wrong, but this checker seems to be ignoring inline comments. For example:

    int num1 = 3; /* this doesn't count*/
    int num2 = 4; // this doesn't count

That's actually a good point that I didn't take into account. From my analysis, neither pygount, slocount, cloc, tokei, analyzo, or cocnt count inline comments, which is a problem. They consider those lines as a source code line.