ENH: additional controls for faMesh construction (#2436)

- move construct from components. Construct with optional IO control

- separate init() method (as per polyMesh) to delay evaluation of
  globalData and base geometry.

- faMesh removeFiles method

ENH: faBoundaryMeshEntries for reading faBoundary files without a mesh

ENH: adjust debug output for {fa,fae,fv,fvs}patchField::New

- add alternative constraint type selection for faePatchField.

- unify handling of "patchType" reading.
  Make less noisy when reporting dictionary defaults.