(defendant was bona fide purchaser of real estate at foreclosure sale because plaintiff failed to prove that defendant was on inquiry notice of any irregularity in prior conveyances of the real estate via power of attorney that allegedly did not give transferor authority to convey the property; but, trial court erred in striking affidavits that plaintiff submitted in support of plaintiff's forgery claim and material factual issue remained concerning whether forgery impacted chain of title and case remanded for trial on forgery issue).