IMPALA-7428: Fix flaky test_shell_command_line::test_large_sql
IMPALA-7428: Fix flaky test_shell_command_line::test_large_sql

This patch fixes the flaky test by rewriting the test to perform a
large query from a non-existent table instead since the test focuses
on Impala shell performance and not Impala performance in general.
This patch also reduces the time limit from 30 seconds to 10 seconds
and increases the number of columns in the query to 10K.

Testing:
- Ran all shell tests

Change-Id: Ic87891f34872da65aac5ce02caf01da1c050efa5
Reviewed-on: http://gerrit.cloudera.org:8080/11201
Reviewed-by: Impala Public Jenkins <039b6b20426ff68ebe492b3021890d8c8fd010c9@cloudera.com>
Tested-by: Impala Public Jenkins <039b6b20426ff68ebe492b3021890d8c8fd010c9@cloudera.com>

cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala