feat!: support constructors in contract creation via `TransactionBuilder.append_create_contract_op`

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 98.65%. Comparing base (196dee2) to head (5cb2848). Report is 1 commits behind head on main.

Additional details and impacted files

[](https://app.codecov.io/gh/StellarCN/py-stellar-base/pull/979?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=StellarCN) ```diff @@ Coverage Diff @@ ## main #979 +/- ## ======================================= Coverage 98.65% 98.65% ======================================= Files 253 253 Lines 13319 13330 +11 ======================================= + Hits 13140 13151 +11 Misses 179 179 ``` | [Flag](https://app.codecov.io/gh/StellarCN/py-stellar-base/pull/979/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=StellarCN) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/StellarCN/py-stellar-base/pull/979/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=StellarCN) | `98.65% <100.00%> (+<0.01%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=StellarCN#carryforward-flags-in-the-pull-request-comment) to find out more. | [Files with missing lines](https://app.codecov.io/gh/StellarCN/py-stellar-base/pull/979?dropdown=coverage&src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=StellarCN) | Coverage Δ | | |---|---|---| | [stellar\_sdk/transaction\_builder.py](https://app.codecov.io/gh/StellarCN/py-stellar-base/pull/979?src=pr&el=tree&filepath=stellar_sdk%2Ftransaction_builder.py&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=StellarCN#diff-c3RlbGxhcl9zZGsvdHJhbnNhY3Rpb25fYnVpbGRlci5weQ==) | `96.92% <100.00%> (ø)` | | | [tests/test\_transaction\_builder.py](https://app.codecov.io/gh/StellarCN/py-stellar-base/pull/979?src=pr&el=tree&filepath=tests%2Ftest_transaction_builder.py&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=StellarCN#diff-dGVzdHMvdGVzdF90cmFuc2FjdGlvbl9idWlsZGVyLnB5) | `100.00% <100.00%> (ø)` | |