use ET timezone consistently in the admin UI

[jtmkrueger]

Resolves 18F/api.data.gov#695

The code here utilizes the pre-existing format_iso8601_ms and removes the format_csv format. I suppose that a compromise could be made to create a new format that is more like the csv format being depricated, but I figured it'd be nicer to just have less formats to worry about and reuse one we're already using.

In the JS, just added some specifics to Parse the timezone as ET and add the timezone to the format string that's being shown to users.

Also adds a couple new tests for these changes.

[GUI]

@jtmkrueger, looks great overall! Just had one proposed tweak to the front-end code to respect a system-wide setting that can control the desired timezone. I'm hoping that session data should be available in this context, but holler if you run into any issues with that.

[GUI]

There's a system-wide analytics.timezone configuration setting that is used throughout the system to determine this type of default time zone to be used. This system setting is exposed during the login in some session data, and that's how the charts know what time zone to use:

api-umbrella/src/api-umbrella/admin-ui/app/routes/stats/base.js

Line 26 in 1cb2bd5

let timezone = this.session.data.authenticated.analytics_timezone;

So to remain consistent with this configuration setting, I'd maybe recommend using that same setting here instead of hard-coding it to ET (even though for the api.data.gov deploy, it's hard-coded to ET):

Suggested change

	return moment(value).tz('America/New_York').format('YYYY-MM-DD HH:mm:ss z');
	return moment(value).tz(this.session.data.authenticated.analytics_timezone).format('YYYY-MM-DD HH:mm:ss z');

[GUI]

Thanks for adding this test coverage! Related to my last comment about leveraging the analytics.timezone setting, the test environment is hard-coded to use America/Denver:

api-umbrella/config/test.yml

Lines 6 to 7 in 1cb2bd5

	analytics:
	timezone: America/Denver

So if you start leveraging that setting, I think you'll need to update these tests to use MDT/MST for their frame of reference. There's technically ways you could also change the timezone in specific tests, but I think that's probably overkill here, so I think just updating these tests to verify the mountain time assumption is sufficient.

[GUI]

This test looks good, but there's one other semi-related test that's failing now: https://github.com/NatLabRockies/api-umbrella/actions/runs/21634777879/job/62359925312#step:5:385

api-umbrella/test/apis/admin/stats/test_users.rb

Lines 99 to 112 in 1cb2bd5

	@user1.created_at.utc.strftime("%Y-%m-%d %H:%M:%S"),
	"2",
	"2015-01-16 00:00:00",
	@user1.use_description,
	], csv[1])
	assert_equal([
	@user2.email,
	@user2.first_name,
	@user2.last_name,
	@user2.website,
	@user2.registration_source,
	@user2.created_at.utc.strftime("%Y-%m-%d %H:%M:%S"),
	"1",
	"2015-01-17 00:00:00",

I think you'll need to update those tests to call user1.created_at.utc.iso8601 and then updated the hard-coded "2015-01-16 00:00:00" strings into ISO8601 format.