Fix locale for monthName/dayName function

[bugmakerrrrrr]

Description

The monthName/dayName function uses Locale.getDefault to get the display name, which may return different results in different env and cause a test error.

org.opensearch.sql.sql.DateTimeFunctionIT > testMonthName FAILED
    java.lang.AssertionError: 
    Expected: iterable with items [[September]] in any order
         but: not matched: <["九月"]>
        at __randomizedtesting.SeedInfo.seed([3027A175091234F:5336A188EBBE09E2]:0)
        at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:18)
        at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:6)
        at org.opensearch.sql.util.MatcherUtils.verify(MatcherUtils.java:173)
        at org.opensearch.sql.util.MatcherUtils.verifyDataRows(MatcherUtils.java:149)
        at org.opensearch.sql.sql.DateTimeFunctionIT.testMonthName(DateTimeFunctionIT.java:801)

Issues Resolved

#2844

Check List

• New functionality includes testing.
  • All tests pass, including unit test, integration test and doctest
• New functionality has been documented.
  • New functionality has javadoc added
  • New functionality has user manual doc added
• Commits are signed per the DCO using --signoff

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[bugmakerrrrrr]

@LantaoJin Would you mind taking a look at this when you have a moment?

[LantaoJin]

@bugmakerrrrrr could u open an issue to discuss? I'm not sure we must fix it. Considering i18n case, perhaps what we need is adding following code in failed IT or just set your env.

    Properties props = GetPropertyAction.privilegedGetProperties();
    props.setProperty("user.language", "en");

[opensearch-trigger-bot]

This PR is stalled because it has been open for 30 days with no activity.

[anasalkouz]

Closing this for now, please feel to re-open if needed.