Core: Fix drop table without purge for REST session catalog

[krvikash]

Issue:
As per documentation of SessionCataog.dropTable says

Drop a table, without requesting that files are immediately deleted.

But the RESTSessionCatalog#dropTable API purges the table even if we are not setting purgeRequested to true.

The issue is happening because, While handling DROP_TABLE request in RESTCatalogAdapter, the call goes to CatalogHandlers.dropTable(Catalog catalog, TableIdentifier ident) when purgeRequested is not set and internally calls catalog.dropTable(ident) that always drops the table with purge.

iceberg/core/src/main/java/org/apache/iceberg/rest/CatalogHandlers.java

Lines 225 to 230 in cd21f68

	public static void dropTable(Catalog catalog, TableIdentifier ident) {
	boolean dropped = catalog.dropTable(ident);
	if (!dropped) {
	throw new NoSuchTableException("Table does not exist: %s", ident);
	}
	}

Fix:
Fix CatalogHandlers.dropTable(Catalog catalog, TableIdentifier ident) API that drops the table without purge.

This PR is to fix the dropTable API for REST Session Catalog for dropping table without purging.

[Fokko]

Great catching this, thanks @krvikash

[singhpk234]

Nice catch !!