[CORE] Propagate fallback reason to union and shuffle exchange

[ulysses-you]

What changes were proposed in this pull request?

This pr does two things

• propagate fallback reason to union and shuffle exchange during validation
• rename UnionExecTransformer to ColumnarUnionExec since we do not transform union in fact

How was this patch tested?

Pass CI

[github-actions]

Thanks for opening a pull request!

Could you open an issue for this pull request on Github Issues?

https://github.com/oap-project/gluten/issues

Then could you also rename commit message and pull request title in the following format?

[GLUTEN-${ISSUES_ID}][COMPONENT]feat/fix: ${detailed message}

See also:

• Other pull requests

[github-actions]

Run Gluten Clickhouse CI

[github-actions]

Run Gluten Clickhouse CI

[ulysses-you]

cc @PHILO-HE @zhouyuan thank you

[PHILO-HE]

Looks good. cc @rui-mo

[GlutenPerfBot]

===== Performance report for TPCH SF2000 with Velox backend, for reference only ====

query	log/native_4489_time.csv	log/native_master_01_22_2024_19a863c0d_time.csv	difference	percentage
q1	32.70	32.31	-0.396	98.79%
q2	24.29	24.07	-0.211	99.13%
q3	36.74	37.08	0.340	100.93%
q4	37.89	38.49	0.604	101.59%
q5	68.92	68.33	-0.589	99.15%
q6	7.05	7.26	0.207	102.93%
q7	83.55	83.81	0.265	100.32%
q8	81.74	83.38	1.647	102.01%
q9	121.22	117.04	-4.176	96.55%
q10	44.86	40.47	-4.394	90.20%
q11	20.11	20.27	0.161	100.80%
q12	29.13	27.53	-1.598	94.51%
q13	45.71	46.48	0.768	101.68%
q14	22.27	15.48	-6.790	69.51%
q15	27.68	28.47	0.798	102.88%
q16	13.58	15.34	1.760	112.97%
q17	101.04	100.56	-0.472	99.53%
q18	145.65	145.52	-0.131	99.91%
q19	14.00	12.41	-1.589	88.65%
q20	27.26	26.33	-0.928	96.60%
q21	223.56	225.25	1.685	100.75%
q22	13.41	13.60	0.188	101.40%
total	1222.32	1209.47	-12.853	98.95%