Improve value skipping at page synchronization

[asfimport]

Currently, value skipping is done one-by-one for page synchronization. There are encodings (e.g. plain) where several values can be skipped at once.

Reporter: Gabor Szadovszky / @gszadovszky
Assignee: Gabor Szadovszky / @gszadovszky

PRs and other links:

• GitHub Pull Request #514

_{Note: This issue was originally created as PARQUET-1389. Please see the migration documentation for further details.}