Create and Display Summary on the Preview page #1169

[heyitsmebev]

The purpose of this PR is allow the user to schedule a delivery and to preview the message before sending.

As a recap, there are two pages called preview that has been created in order to display specific details of a message. In addition, the old "preview" pages have now been converted into a more general schedule page where the user can select delivery time.

This discussion here can help understand how the pages should look: #815 (comment)
On the preview page for batch jobs, user should be able to see the following:

• Preview list (csv table) with disclaimer caption: "Note: Only the first 5 rows are displayed here."
• SMS Preview Message (message details at the top)
  • File name csv
  • Template name
  • Scheduled: Now or timestamp depending on user's actions
• Preview of the message
• User should see either a "Send" button or "Schedule" button depending user's actions
• User should be able to use back link to go to previous page
• Show Recipients list header and csv file title

On the preview page for one-off jobs, user should be able to see the following:

• SMS Preview Message (message details at the top)
  • Template name
  • Scheduled: Now or timestamp depending on user's actions
• Preview of the message
• User should see either a "Send" button or "Schedule" button depending user's actions

On the schedule page, user should be able to see:

• Select delivery time title
• Scheduling form
• "Preview" button

Screenshots from Figma and understanding the flow: https://www.figma.com/file/aAWhlPzOP6kfVFnCCAfSZZ/notify.gov?type=design&node-id=2020-3624&mode=design&t=D1nRLZLNSXonIYCN-0

This image is to help provide an idea of what the preview page will look like when a user sends a batch message.

[ccostino]

@heyitsmebev just noting here as a follow-up from the last discussion we had that the message parts calculations during the sending preview were not needed for this, so it should be ready for full review as it is!

[terrazoon]

LGTM with a couple minor comments.

[ccostino]

Thank you, @heyitsmebev!

All looks good to me, but I wanted to check on one thing with the preview form and the adjustment with the CSRF (cross-site request forgery) piece that is removed from it. I want to be clear on that change and why it's no longer needed, or adjust if it does have to go back in.

Thanks!

[ccostino]

Thanks, @heyitsmebev! 🎉