[SPARK-20926][SQL] Removing exposures to guava library caused by directly...

[SPARK-20926][SQL] Removing exposures to guava library caused by directly accessing  SessionCatalog's tableRelationCache

There could be test failures because DataStorageStrategy, HiveMetastoreCatalog and also HiveSchemaInferenceSuite were exposed to guava library by directly accessing SessionCatalog's tableRelationCacheg. These failures occur when guava shading is in place.

## What changes were proposed in this pull request?
This change removes those guava exposures by introducing new methods in SessionCatalog and also changing DataStorageStrategy, HiveMetastoreCatalog and HiveSchemaInferenceSuite so that they use those proxy methods.

## How was this patch tested?

Unit tests passed after applying these changes.

Author: Reza Safi <rezasafi@cloudera.com>

Closes #18148 from rezasafi/branch-2.2.

(cherry picked from commit 1388fdd7)