Simplify push notification workflow by merging templates and draft status

[MizukiTemma]

Short description

This PR introduced a new workflow for the push notification feature.

Proposed changes

• Remove draft, is_template and template_name from PushNotification (incl. migration)
• Remove parts related to those fields from the template, form, view, Typescript file and management command
• Chanhe the workflow as in the design
• Add "Copy" option in each row of the push notification list
• Adjust API, fixture, tests

Side effects

• Should be none 🙈

Faithfulness to issue description and design

• During the design review we all forgot that there is an option to schedule a push notification. "Send" button is called "Schedule" as before, if the opened push notification is not yet sent and has a scheduled send date.
• MT is not yet integrated into the workflow. It will be implemented as Translation of (Push-)News with MT #2640 once this issue is completed.

How to test

Resolved issues

Fixes: #2639

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Pull Request Review Guidelines

[hannaseithe]

Thank you for this big PR. Everything works well and the code is clean. I just have a few thoughts about the flow of "scheduling" and of "copying" - which I could not really grasp from the design plan, but feel should be considered.

1.) I feel that the workflow with scheduling is still not really optimized. Like: if I should only be able to schedule a pn after it has been saved, I feel I shouldnt be able to select "Automatisch senden" and set the date and time during the save process. It should only show when I have the option to schedule. The other way around it is confusing that when I only click on "Speichern", but have selected a date and time, it will save that and show it in the list as "Scheduled for" that date&time.

1a.) If we already have scheduled (actually scheduled, not just saved with a date and time) a notification, is it intended that the notification can be re-scheduled? If yes, maybe the button should show as "Re-schedule"? If no , the "schedule" button should not show

2.) Maybe when creating a copy, the form should open with that newly created copy. (Instead of just appear in the list)

[MizukiTemma]

@hannaseithe
Thank you for review 😸 I'd leave the question to @osmers @hauf-toni and @laravoelk but will provide some context.

1.) I feel that the workflow with scheduling is still not really optimized. Like: if I should only be able to schedule a pn after it has been saved, I feel I shouldnt be able to select "Automatisch senden" and set the date and time during the save process. It should only show when I have the option to schedule. The other way around it is confusing that when I only click on "Speichern", but have selected a date and time, it will save that and show it in the list as "Scheduled for" that date&time.

We actually didn't look deeply into the workflow with scheduling at the time of design discussion (as we all forgot that option 😅)

The background of the birth of this "saving" step before sending is to gurantee translations in other languages are surely there before user dispatchs the push notification (MT will be connected to the PN form in #2640 ).

1a.) If we already have scheduled (actually scheduled, not just saved with a date and time) a notification, is it intended that the notification can be re-scheduled? If yes, maybe the button should show as "Re-schedule"? If no , the "schedule" button should not show

Re-scheduling is possible in the current implementation (before this PR) too.

2.) Maybe when creating a copy, the form should open with that newly created copy. (Instead of just appear in the list)

That sounds a good idea 👀

[hauf-toni]

1. Thank you for your input. I think that makes even more obvious that what @hannaseithe stated is right from a users perspective. The flow should be
   New Push Notification → Edit PN → Save PN → Schedule for Sending at a later Point. This also considers our technical specification that for translation it has to be saved first and makes it scalable for when MT will be introduced at a later point.

1a.) I agree with @hannaseithe. @MizukiTemma maybe you can clarify how exactly that would be possible? Unfortunately I can't access this functionality in the Testumgebung.

2. Yes, agreed.

[MizukiTemma]

@hannaseithe
Your suggestions are applied 😸 Please check.

[jonbulz]

I tested the new workflow in my local environment and everything seemed to work as expected. Code looks good to me. Thanks! :)