Make vault client retry submissions for RPC timeout errors

[ebma]

Context

Sometimes, our RPC nodes are slow or unresponsive and it happens that transaction submissions time out because of this error. The vault client currently does not retry the submission of the transaction for those errors, but it should.

TODO

Make the vault client retry the submission of extrinsics for timeout errors thrown by the RPC client.

[ebma]

@pendulum-chain/product this feature will prevent users from having to wait hours for the execution of bridging requests even if our RPC nodes are slow.

[annatekl]

Hey team! Please add your planning poker estimate with Zenhub @b-yap @bogdanS98 @ebma @gianfra-t @TorstenStueber