[SPARK-7067] [SQL] fix bug when use complex nested fields in ORDER BY

This PR is a improvement for https://github.com/apache/spark/pull/5189.

The resolution rule for ORDER BY is: first resolve based on what comes from the select clause and then fall back on its child only when this fails.

There are 2 steps. First, try to resolve `Sort` in `ResolveReferences` based on select clause, and ignore exceptions. Second, try to resolve `Sort` in `ResolveSortReferences` and add missing projection.

However, the way we resolve `SortOrder` is wrong. We just resolve `UnresolvedAttribute` and use the result to indicate if we can resolve `SortOrder`. But `UnresolvedAttribute` is only part of `GetField` chain(broken by `GetItem`), so we need to go through the whole chain to indicate if we can resolve `SortOrder`.

With this change, we can also avoid re-throw GetField exception in `CheckAnalysis` which is little ugly.

Author: Wenchen Fan <cloud0fan@outlook.com>

Closes #5659 from cloud-fan/order-by and squashes the following commits:

cfa79f8 [Wenchen Fan] update test
3245d28 [Wenchen Fan] minor improve
465ee07 [Wenchen Fan] address comment
1fc41a2 [Wenchen Fan] fix SPARK-7067