[SPARK-49748][CORE][FOLLOWUP] Add getCondition and deprecate `getEr…

…rorClass` in `QueryCompilationErrorsSuite`

### What changes were proposed in this pull request?
The pr is following up apache#48196

### Why are the changes needed?
Revise the logic of the newly added logic.

### Does this PR introduce _any_ user-facing change?
No.

### How was this patch tested?
Pass GA.

### Was this patch authored or co-authored using generative AI tooling?
No.

Closes apache#48416 from panbingkun/SPARK-49748_FOLLOWUP.

Authored-by: panbingkun <[email protected]>
Signed-off-by: Max Gekk <[email protected]>

sql/core/src/test/scala/org/apache/spark/sql/errors/QueryCompilationErrorsSuite.scala

@@ -1003,7 +1003,7 @@ class QueryCompilationErrorsSuite
         val exception = intercept[AnalysisException] {
           sql(queryWithTrailingComma)
         }
-        assert(exception.getErrorClass === "TRAILING_COMMA_IN_SELECT")
+        assert(exception.getCondition === "TRAILING_COMMA_IN_SELECT")
       }
 
       val unresolvedColumnErrors = Seq(
@@ -1017,7 +1017,7 @@ class QueryCompilationErrorsSuite
         val exception = intercept[AnalysisException] {
           sql(query)
         }
-        assert(exception.getErrorClass === "UNRESOLVED_COLUMN.WITH_SUGGESTION")
+        assert(exception.getCondition === "UNRESOLVED_COLUMN.WITH_SUGGESTION")
       }
 
       // sanity checks