Allow GetChallenge at any position during TA execution

This commit contains newly generated code (model repo
rev:64873c79081922a7969f6ed01d16efb04911cdbf).

Previously GetChallenge was only allowed by according states before the
certificate verification process and after MSE:SetAt. The new
implementation allows GetChallenge at any position during TA trhoug
usage of history states.

processCommandGetChallenge now needs to generate a new challenge
regardless of the previous challenge state.

processCommandExternalAuthenticate now needs to check the existence of a
challenge and throws SW 6985 if no challenge was generated yet.
Allow arbitrary tag order in APDUs

According to TR-03110-3 Version 2.20 beta2 section B.14. APDU
Specification: "The receiver SHOULD be capabale [sic] to process APDUs
with data objects given in any order."
Merge pull request #18 from weinhold/arbitrary-tag-order-in-apdus

Allow arbitrary tag order in APDUs
Merge pull request #19 from alexfupp/taAcceptGetChallengeAtAnyPosition

Allow GetChallenge at any position during TA execution