[HMPhaseField] add hydromechanical phase-field process

This process addresses the hydraulic fracture problem using the phase-field method (Reference paper with some newly developed features). This process includes three sub-processes, i.e., the phase-field v, the pressure p and the displacement u, in which the fixed stress split is used to tackle u-p coupling within a local coupling iteration. The sub-processes are verified separately by linear elastic problem (M), fluid flow in fracture (H), consolidation problem (HM), fracture problem (MPhaseField) and KGD (Reference paper) hydraulic fracture problem (HMPhaseField). Further benchmarks are being prepared and might be included in this or the following MR.

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2. Tests covering your feature were added?
3. Any new feature or behavior change was documented?