The "Name" input field validation should not be case sensitive when entering existing experiments name with different cases

[Softvision-RemusDranca]

[Affected versions]:

• Firefox Release 66.0 and above
• Chrome 72.0.3626.121

[Affected Platforms]:

• All Windows
• All Mac
• All Linux

[Prerequisites]:

• You are logged with your LDAP account on the "https://experimenter.stage.mozaws.net/" website.
• Have an experiment created on the Experimenter stage website with the name (eg: the experiment is named "Owner").
• Have a second experiment created on the Experimenter stage website with a different name.

[Steps to reproduce]:

1. Open the browser with the profile from prerequisites and navigate to "https://experimenter.stage.mozaws.net/".
2. Open the second created experiment from prerequisites.
3. Click the "Edit" button from "Overview" section.
4. Enter the name from the first created experiment starting with a lowercase (eg.: "owner").
5. Click the "Save Draft" button and observe the behavior.

[Expected result]:

• An error message that informs the user that the name is already used, is displayed.

[Actual result]:

• No error message is displayed, the field is wrongly validated (green border), but the the draft is not saved.

[Notes]:

• This issue is not reproducible if the name is inserted with the same cases.
• Attached is a screen recording of the issue:

[jaredlockhart]

Good catch! Super subtle, why isn't the form reporting errors? This is actually a duplicate of https://github.com/mozilla/experimenter/issues/1129

[Softvision-RemusDranca]

I have verified this issue and is no longer reproducible on Experimenter stage "https://stage.experimenter.nonprod.dataops.mozgcp.net/" website after the v2.28.0 stage deployment. Tested on Windows 10x64, Mac 10.14 and Arch Linux 4.16.6 x64.