Fix tests that do not converge

Description

We need to add in checks to all the benchmark tests to ensure that the problem converges successfully before comparing expected values.

self.assertTrue(prob.result.success)

Example

The following tests do not currently give prob.result.success = True:

test_bench_FwFm.py:TestBenchFwFmSerial.test_bench_FwFm_IPOPT
test_bench_FwGm.py:bench_test_swap_1_GwFm_IPOPT
test_bench_GwFm.py:ProblemPhaseTestCase.bench_test_swap_1_GwFm_IPOPT (doesn't run under testflo runs in PR).
test_FLOPS_detailed_landing.py:TestFLOPSDetailedLanding.bench_test_IPOPT
test_bench_offdesign.py:Test2DOFOffDesign.test_alternate_mission_match SNOPT

These tests are fixed. [KTM]
test_bench_FwFm.py:TestBenchFwFmSerial.test_bench_FwFm_SNOPT exit code 3 requested accuracy not achieved
test_bench_FwGm.py:* (close, but doesn't get a 0,1) [added by KTM]
test_bench_GwFm.py:ProblemPhaseTestCase.bench_test_swap_1_GwFm_SNOPT (doesn't run in testflo or PR, runs in merge queue).
test_FLOPS_based_sizing_N3CC.py:ProblemPhaseTestCase.bench_test_sizing_N3CC exit code 41 current point cannot be improved

These tests no longer exist. Their replacements have the success assert. [KTM]
test_off_design_FwFm.py:TestOffDesign.test_off_design_IPOPT
test_off_design_FwFm.py:TestOffDesign.test_off_design_SNOPT
test_off_design_GwGm.py:TestOffDesign.test_off_design_IPOPT
test_off_design_GwGm.py:TestOffDesign.test_off_design_SNOPT

Aviary Version

0.10.0-dev

Relevant environment information

No response