(a) This chapter waives sovereign immunity only for the benefit of:
(1) a party to the contract that is the subject of a dispute under Section 113.002; or
(2) the assignee of a party to the contract, if assignment of an interest in the contract is permitted by the terms of the contract.
(b) Except for an assignment described by Subsection (a)(2), a party authorized by this chapter to sue for a cause of action of breach of contract may not transfer or assign that cause of action to any person.