Fix release date issue in Safari

[Dananji]

Fixes #4005

When editing admin sets in Safari, the embargo release date format shows up as yyyy-mm-dd and is not able to save dates in the format mm/dd/yyyy (expected format) sometimes.

Changes proposed in this pull request:

• Format date values on page load and on submit into desired date format.

Guidance for testing, such as acceptance criteria or new user interface behaviors:

• Login as an admin user in Safari
• Create an admin set collection and save
• Select the Release and Visibility tab
• See the placeholder text for the release dates fields
• Select "Depositor must choose embargo"
• Enter date as 10/23/2025 and save
• See the date appears in the same format as it was entered

@samvera/hyrax-code-reviewers

[Dananji]

According to the coveralls report, code coverage is reduced in app directory which does not include assets and views directories and this PR contains changed files only in those 2. I'm not sure, whether I'm reading this correctly.
Anyone's help on this is appreciated. Thanks.
@samvera/hyrax-code-reviewers

[no-reply]

we're okay to ignore coveralls. there's a proposal to remove it altogether since it does this constantly.

GitHub is setup to not require it, but still produces the scary red X.

Merge on this is just blocked by a review. Hoping someone with frontend expertise can take a peek at this.

cc: @adamjarling

[jrgriffiniii]

This is fantastic, thank you very much for this @Dananji! A quick question: why was var used in place of let here for ES6? My assumption is that the former is preferred: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/let#Temporal_dead_zone

[adamjarling]

Agree with @jrgriffiniii.. for any es6/es7 JavaScript lets stick with either let or const variable declarations?

[Dananji]

Sure! I will make that change

[adamjarling]

Code looks good to me.