Update the Profile / SSH keys datepicker element to GlDatepicker

Problem to solve

The current Profile / SSH Keys datepicker is a input type="date" element. This causes the input to be inconsistent across different browsers:

The input UI generally varies from browser to browser

The input also doesn't match the datepicker on Profile / Personal Access Tokens which uses the GlDatepicker component.

Screenshots

Current (SSH Keys)	datepicker (Personal Access Tokens)

Proposed implementation

Replace the Profile / SSH Keys datepicker with a GlDatepicker component.

Availability & Testing

We have e2e tests that use the expiry date field and might need an update. Please run the package-and-qa job to ensure e2e tests are fine.