Excited-State Dynamics Leading either to Triplet Formation or Coordinative Expansion following Photolysis of Cu(II)-5,10,15,20-&lt;em&gt;meso-tetrakis&lt;/em&gt;(phenyl)porphyrin or Cu(II)-5,10,15,20-&lt;em&gt;meso-tetrakis&lt;/em&gt;(N-methylpyridium-4-yl)porphyrin: A DFT, TD-DFT, Luminescence and Femtosecond Time-Resolved Absorbance Study