Allow str addresses as change address in txbuilder

[nielstron]

Is your feature request related to a problem? Please describe.
A lot of users put a Bech32 encoded address as change address in the txbuilder, which seems natural as a user flow. The returned error message is usually quite obscure.

Describe the solution you'd like
For this reason, the txbuilder should check and optimally directly transform a passed-in str object to a PyCardano address object to reduce friction.

Describe alternatives you've considered
The txbuilder could check that it is passed an address object and raise an error otherwise. The process to transform a string to address is very automatizable though, so it should directly apply this.

Additional context
CC @while0x1

[cffls]

Looks like this issue will be resolved in the next release with this commit: 4bf6a62

Any string address passed to transaction output will be converted automatically.