fix: Add support for the new Japanese Era (Reiwa) to ICU

[jefgen]

Description of Change

This change backports changes from the upstream ICU project's maintenance release for ICU 62.2 in order to enable support for the new Japanese Era "Reiwa" in Chromium 69 (which uses ICU version 62.1).

Upstream release: http://site.icu-project.org/download/62

Background information:

The current Japanese Emperor will abdicate on April 30, 2019. The current era Heisei (平成) will end on that date, and a new Japanese era Reiwa (令和) will start on May 1, 2019. Until the end of April, the year in Japanese calendar is Heisei 31 (平成31年), but from May 1 on it will be changed to Reiwa 1 (令和元年).

Existing ICU versions support Japanese calendar date calculation and formatting, but the new era Reiwa was not known when these versions were released. Therefore, these ICU versions produce an incorrect year format when using the Japanese calendar, which is the default calendar for the Japanese locale.

This PR removes the patch for the "placeholder" era name support that was added in PR #17518, and replaces it with a new patch that adds support for the official new era name, and bumps the ICU version from 62.1 to 62.2.

With this change you now get correct results for various JavaScript date/time formatting APIs for the Japanese calendar.

Additionally, this PR also backports some additional bug fixes from upstream as well.

This PR also includes the following fixes/updates:

• Update IANA time zone data to tzdata2019a.
• Japanese calendar: era calculation should use local time, not UTC.
• Japanese calendar: use all valid eras for calendar calculations.
• Fix LocalMemory move constructor deletion issue.

This change requires re-generating the checked-in Chromium ICU data files (ex: icudtl.dat) in order for them to have the updated data for the new era name.
Note: All of the checked-in files are be regenerated, even though the Electron project only uses the "common" one.

Screenshots:

Before, with the placeholder era not enabled. (Incorrectly showing dates after May 1 2019 using the Heisei era).

After, correctly using the new era Reiwa for dates after April 30, 2019.

You can also see the version bump for icu and tz in the screenshot.

Sample code (for testing):

<p>Outputs:</p>
<form>
<textarea id="jaEraOutputs" rows="9" cols="60"></textarea>
</form>

<script type="text/javascript">
    // Heisi Era will end on April 30, 2019 so pick a date before.
    var dateHeisi = new Date(Date.UTC(2019, 01, 15, 3, 0, 0));
    // New Era starts on May 1, 2019.
    var dateNew = new Date(Date.UTC(2019, 05, 02, 3, 0, 0));
    
    var out = document.getElementById("jaEraOutputs");
    out.value = "";
    out.value += "Heisi: \n";
    out.value += "\t ja-JP:  " + dateHeisi.toLocaleString('ja-JP-u-ca-japanese', {era: 'long'}) + "\n";
    out.value += "\t en-US:  " + dateHeisi.toLocaleString('en-US-u-ca-japanese', {era: 'long'}) + "\n";
    out.value += "\n";
    out.value += "New Era: \n";
    out.value += "\t ja-JP:  " + dateNew.toLocaleString('ja-JP-u-ca-japanese', {era: 'long'}) + "\n";
    out.value += "\t en-US:  " + dateNew.toLocaleString('en-US-u-ca-japanese', {era: 'long'}) + "\n";
</script>

Checklist

• PR description included and stakeholders cc'd. [CC: @alexeykuzmin] [FYI for @aandrejs , @daniel-ju]
• npm test passes
• tests are changed or added
• relevant documentation is changed or added
• PR title follows semantic commit guidelines
• PR release notes describe the change in a way relevant to app developers, and are capitalized, punctuated, and past tense.

Release Notes

Notes:

• Added support for the new Japanese Era Reiwa (令和) to JavaScript date/time formatting APIs.
• Updated ICU library to version 62.2
• Updated IANA time zone data to tzdata2019a.

[deepak1556]

Related upstream PR: unicode-org/icu#610

[release-clerk]

Release Notes Persisted

• Added support for the new Japanese Era Reiwa (令和) to JavaScript date/time formatting APIs.
• Updated ICU library to version 62.2
• Updated IANA time zone data to tzdata2019a.

[omarkilani]

@jefgen is a similar fix needed on the 5.x branch?