[SPARK-35037][SQL] Recognize sign before the interval string in literals

[MaxGekk]

What changes were proposed in this pull request?

1. Extend SQL syntax rules to support a sign before the interval strings of ANSI year-month and day-time intervals.
2. Recognize - in AstBuilder and negate parsed intervals.

Why are the changes needed?

To conform to the SQL standard which allows a sign before the string interval, see "5.3 <literal>":

<interval literal> ::=
  INTERVAL [ <sign> ] <interval string> <interval qualifier>
<interval string> ::=
  <quote> <unquoted interval string> <quote>
<unquoted interval string> ::=
  [ <sign> ] { <year-month literal> | <day-time literal> }
<sign> ::=
    <plus sign>
  | <minus sign>

Does this PR introduce any user-facing change?

Should not because it just extends supported intervals syntax.

How was this patch tested?

By running new tests in interval.sql:

$ build/sbt "sql/testOnly *SQLQueryTestSuite -- -z interval.sql"

[SparkQA]

Kubernetes integration test starting
URL: https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder-K8s/41819/

[SparkQA]

Kubernetes integration test status failure
URL: https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder-K8s/41819/

[SparkQA]

Test build #137239 has finished for PR 32134 at commit 9b44a38.

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

[MaxGekk]

The GA "Build and test / Scala 2.13 build with SBT (pull_request)" failed but I checked scala 2.13 locally:

$ ./dev/change-scala-version.sh 2.13
$ ./build/sbt -Pscala-2.13 compile
[success] Total time: 145 s (02:25), completed Apr 13, 2021 8:50:50 AM

[MaxGekk]

Merging to master. Thank you @srowen for review.