Remove gon.global experiment scoping and organize helpers

What does this MR do?

• Attempts to consolidate experiment helper/utils/etc javascript under a common directory.
• Removes the global scope on Gon as putting it in global causes it to persist past one request cycle and becomes troublesome if you try to base conditionals on the experiment in gon for deciding on showing with v-if as seen in this mr
• makes use of constants for schema.

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Related to #296640