GH-149: Apply the client-side filter on the legacy sorting/pagination read path

[jtnelson]

Closes #149

Summary

On the legacy read path for Concourse servers without native sorting and pagination support (older than 0.10), any read that combined a client-side Predicate filter with an Order or a Page ignored the filter entirely, so load, loadAny, find, and findAny overloads that accept a filter could return records the filter rejects. This change applies the filter on that path.

Behavior

• The filter now applies to legacy-path results whenever an Order or a Page is requested.
• Pagination operates over the universe of records that pass the filter, so a page is populated only from records the filter accepts. This matches the behavior on servers with native sorting and pagination support.
• Servers with native sorting and pagination support are unaffected.

Scope

• Only the legacy read path changes. Regression coverage lives in GH149.