[C++][Parquet] Parquet page index read support

[asfimport]

Implement read support for parquet page index and expose it from the reader API.

Reporter: Gang Wu / @wgtmac
Assignee: Gang Wu / @wgtmac

PRs and other links:

• GitHub Pull Request #14964

_{Note: This issue was originally created as ARROW-18434. Please see the migration documentation for further details.}

[pitrou]

@wgtmac Can you add a comment so that we can assign you here?

[wgtmac]

@wgtmac Can you add a comment so that we can assign you here?

Thanks @pitrou!