Get rid of preloading options and require use of `ArrowReaderOptions` in ParquetObjectReader get_metadata.

**Is your feature request related to a problem or challenge? Please describe what you are trying to do.**
We should use `ArrowReaderOptions` in ParquetObjectReader get_metadata, and we can get rid of preloading options, this should be more reasonable instead of two options.

Details:
https://github.com/apache/arrow-rs/pull/8857#pullrequestreview-3473750116

**Describe the solution you'd like**

**Describe alternatives you've considered**

**Additional context**

Start at the ParquetObjectReader get_metadata entry point and review the linked pull-request discussion, especially the use of ArrowReaderOptions and the existing preloading options. Confirm the intended API consolidation and identify the affected tests or callers before changing the interface; done means get_metadata uses ArrowReaderOptions without the separate preloading options.

Written by the indexing model from the issue text.