When writing parquet plaintext footer files `footer_signing_key_metadata` is not included, encryption alghoritm is always written in footer

[rok]

Describe the bug
When writing plaintext footer footer_signing_key_metadata is not included. This means a key retriever cannot be used to read files with plaintext footers.

Additionally, the footer encryption algorithm is currently written inside the footer even when the footer is encrypted but this is redundant and goes against the spec:
https://github.com/apache/parquet-format/blob/f1fd3b9171aec7a7f0106e0203caef88d17dda82/src/main/thrift/parquet.thrift#L1294-L1298

To Reproduce
Written plaintext footer file will not include footer_signing_key_metadata.
Written encrypted non-plaintext footer files shouldn't include encryption_algorithm.

Additional context
This is was caused by #7439