Fix: fix python readMessageBegin return value type error

[bwangelme]

What did this PR do?

In the function transport.TTransport.readAll, when the sz<0, the type of name is str.

But when the sz>0, the type of name is bytes.

They should return the same types.

I use the binary_to_str to convert the type of name

Test

I write a unittest method test_TBinaryProtocol_no_strict_write_read to test my changes. It passed.

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[Jens-G]

It is not a trivial change, so I didn't create an Apache Jira ticket.

Sorry but that gives no meaning.

[bwangelme]

Sorry but that gives no meaning.

Ok, Delete it from the description.​

[bwangelme]

• cross-test (java, go,rs) (pull_request)
• cross-test (kotlin, go,rs) (pull_request)
• cross-test (go, java,kotlin) (pull_request)
• cross-test (rs, java,kotlin) (pull_request)
• cross-test (rs, swift) (pull_request)
• cross-test (rs, go,rs) (pull_request)
• cross-test (swift, go,rs) (pull_request)

These ci are failed. It seems unrelated to my python changes.