Catalytic and Stoichiometrically Directed Synthesis of Less Accessible Bromothiophenes and Bromobithiophenes. Trapping and Characterization of Catalytic Intermediates of trans-PdBr(C4H4-nBrn-1S-C) (PPh3)2 (n = 1—4), trans-PdBr(C8H4BrS2-C) (PPh3)2, and trans,trans-Pd2Br2 (μ-C8H6-nBrn-2S2-C,C′) (PPh3)