[SPARK-13234] [SQL] remove duplicated SQL metrics

[davies]

For lots of SQL operators, we have metrics for both of input and output, the number of input rows should be exactly the number of output rows of child, we could only have metrics for output rows.

After we improved the performance using whole stage codegen, the overhead of SQL metrics are not trivial anymore, we should avoid that if it's not necessary.

This PR remove all the SQL metrics for number of input rows, add SQL metric of number of output rows for all LeafNode. All remove the SQL metrics from those operators that have the same number of rows from input and output (for example, Projection, we may don't need that).

The new SQL UI will looks like:

[andrewor14]

@zsxwing

[SparkQA]

Test build #51066 has finished for PR 11163 at commit 319f30d.

• This patch fails Scala style tests.
• This patch merges cleanly.
• This patch adds no public classes.

[zsxwing]

LGTM

[SparkQA]

Test build #51069 has finished for PR 11163 at commit 84af95d.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #2535 has finished for PR 11163 at commit ecacbfc.

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

[davies]

Merging into master, thanks!

[SparkQA]

Test build #51084 has finished for PR 11163 at commit ecacbfc.

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