chore: refactor endpageblock to generic folder

[kathleenkhy]

Problem

Related to PR (#7232) to refactor by moving EndPageBlock.tsx file to a generic folder (out of the public-form folder) - this is to reduce confusion that the EndPageBlock.tsx is not entirely isolated to the public-form context and may cause downstream bugs and issues if the component is rendered incorrectly.

Closes FRM-1710

Solution

By moving EndPageBlock.tsx to a generic folder that is not within public-form or admin-form

Tests

• Create a non-payment form
• Proceed to the Thank You page tab

MRF Form test

• Create an MRF form
• Create 2 workflows
• Submit the 1st workflow - the Submit another response button should be present
• Submit the 2nd workflow - the Submit another response button should not be present

[linear]

FRM-1710 Move EndPageBlock from `public-form` folder to generic component folder

[KenLSM]

LGTM, but let's merge it after GA tomorrow.