[SPARK-32072][CORE][TESTS] Fix table formatting with benchmark results

[MaxGekk]

What changes were proposed in this pull request?

Set column width w/ benchmark names to maximum of either

1. 40 (before this PR) or
2. The length of benchmark name or
3. Maximum length of cases names

Why are the changes needed?

To improve readability of benchmark results. For example, MakeDateTimeBenchmark.

Before:

make_timestamp():                         Best Time(ms)   Avg Time(ms)   Stdev(ms)    Rate(M/s)   Per Row(ns)   Relative
------------------------------------------------------------------------------------------------------------------------
prepare make_timestamp()                           3636           3673          38          0.3        3635.7       1.0X
make_timestamp(2019, 1, 2, 3, 4, 50.123456)             94             99           4         10.7          93.8      38.8X
make_timestamp(2019, 1, 2, 3, 4, 60.000000)             68             80          13         14.6          68.3      53.2X
make_timestamp(2019, 12, 31, 23, 59, 60.00)             65             79          19         15.3          65.3      55.7X
make_timestamp(*, *, *, 3, 4, 50.123456)            271            280          14          3.7         270.7      13.4X

After:

make_timestamp():                            Best Time(ms)   Avg Time(ms)   Stdev(ms)    Rate(M/s)   Per Row(ns)   Relative
---------------------------------------------------------------------------------------------------------------------------
prepare make_timestamp()                              3694           3745          82          0.3        3694.0       1.0X
make_timestamp(2019, 1, 2, 3, 4, 50.123456)             82             90           9         12.2          82.3      44.9X
make_timestamp(2019, 1, 2, 3, 4, 60.000000)             72             77           5         13.9          71.9      51.4X
make_timestamp(2019, 12, 31, 23, 59, 60.00)             67             71           5         15.0          66.8      55.3X
make_timestamp(*, *, *, 3, 4, 50.123456)               273            289          14          3.7         273.2      13.5X

Does this PR introduce any user-facing change?

No

How was this patch tested?

By re-generating benchmark results for MakeDateTimeBenchmark:

$ SPARK_GENERATE_BENCHMARK_FILES=1 build/sbt "sql/test:runMain org.apache.spark.sql.execution.benchmark.MakeDateTimeBenchmark"

in the environment:

Item	Description
Region	us-west-2 (Oregon)
Instance	r3.xlarge
AMI	ubuntu/images/hvm-ssd/ubuntu-bionic-18.04-amd64-server-20190722.1 (ami-06f2f779464715dc5)
Java	OpenJDK 64-Bit Server VM 1.8.0_252 and OpenJDK 64-Bit Server VM 11.0.7+10

[SparkQA]

Test build #124415 has finished for PR 28906 at commit f0598b5.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[MaxGekk]

@srowen @dongjoon-hyun Please, review this PR.

[SparkQA]

Test build #124428 has finished for PR 28906 at commit e1a242e.

• This patch fails build dependency tests.
• This patch merges cleanly.
• This patch adds no public classes.

[MaxGekk]

jenkins, retest this, please

[SparkQA]

Test build #124429 has finished for PR 28906 at commit e1a242e.

• This patch fails build dependency tests.
• This patch merges cleanly.
• This patch adds no public classes.

[MaxGekk]

jenkins, retest this, please

[SparkQA]

Test build #124432 has finished for PR 28906 at commit e1a242e.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[srowen]

The formatting changes are positive of course. Most of the numbers didn't change much at all; these kinda of did, some much more than a few stdevs. Just checking, it was on the same hardware as in the heading?

[cloud-fan]

I think so, as the head is written by the benchmark framework automatically.

[cloud-fan]

thanks, merging to master!