Refactor HighsCliqueTable::addClique

[fwesselm]

• Refactor HighsCliqueTable::addClique and related code
• HighsCliqueTable::addClique now checks if an equality clique with two elements is passed and automatically considers the complemented clique as well (i.e. x_1 + x_2 <= 1 and (1 - x_1) + (1 - x_2) <= 1, which is useful for equality cliques identified by solution enumeration).
• Computational results are very similar to the baseline, so average performance is not affected very much. However, the new code is very helpful on individual models.

[fwesselm]

code-coverage is falling with the following error:

lcov: ERROR: 'exclude' pattern 'app/CLI11*' is unused.
	(use "lcov --ignore-errors unused ..." to bypass this error)

[Opt-Mucca]

Very nice refactor with foundCover! The code is way nicer to read now. Two questions:

• Now all substitutions are resolved before "checking" the clique. Is there any reason this wasn't done before (looks to be neater and potentially more efficient)
• I'm not understanding why the complemented inequality clique is valid here (even if it's only for size 2).

[galabovaa]

code-coverage is falling with the following error:

lcov: ERROR: 'exclude' pattern 'app/CLI11*' is unused.
	(use "lcov --ignore-errors unused ..." to bypass this error)

Thank you, @fwesselm

Fixed this in #2757

[Opt-Mucca]

Cleared up some misunderstanding on my part!