Add BoundManager support to CDPWLC

[AleksandarZeljic]

This PR introduces support in the ContextDependentPiecewiseLinearConstraint
class to store bounds using a BoundManager object. Like other context-dependent
members, once the BoundManager object is registered, all the bounds are stored and
retrieved through the BoundManager.

This PR introduces methods to interface between local and global means of
storing bounds. For this purpose the following methods are introduced in
ContextDependentPiecewiseLinearConstraint class:

bool existsLowerBound( unsigned variable );
unsigned getLowerBound( unsigned variable );
void setLowerBound( unsigned variable );
bool existsUpperBound( unsigned variable );
unsigned getUpperBound( unsigned variable );
void setUpperBound( unsigned variable );

All calls to check, read or write local bound arrays are replaced with calls to
the introduced wrapper methods in all the constraint classes:

• AbsoluteValueConstraint
• DisjunctionConstraint
• MaxConstraint
• ReluConstraint
• SignConstraint

Respective test classes have been updated to include existing tests in both the
preprocessing and context-dependent mode, preserving existing functionality.

Finally, all modified files have also been reformatted to conform to the style
guidelines.

[AleksandarZeljic]

@guykatzz Hi Guy, the PR is finally ready for review. It seems big, but only one file needs serious scrutiny - MaxConstraint.cpp, the rest of the constraint classes are pretty simple changes.

The test files have big additions, but they are all repeating existing test cases with BoundManager initialized. So a quick skim to make sure that each introduced test initializes the BoundManager should be enough.