“The insurance may provide that, when considering what may be regarded as one Claim … (a) all Claims against any one or more Insured arising from: (i) one act or omission; (ii) one series of related acts or omissions; (iii) the same act or omission in a series of related matters or transactions; (iv) similar acts or omissions in a series of related matters or transactions … will be regarded as one Claim.”