Syntheses, Structures, and Antimicrobial Activities of Light-Stable and Di- and Mononuclear Silver(I) Carboxylate Complexes Composed of Triphenylphosphine, and Chiral and Racemic Forms of 2-Pyrrolidone-5-carboxylic Acid (H2pyrrld). A Variety of Ag–O Bonding Modes in the Silver(I) Complexes Constructed with Hard Oxygen and Soft Phosphorus Atoms