Make webhook Response Body detailed when webhook is inactive

[Young-Lord]

Currently, when user click Test Delivery for an inactivate webhook, Gitea will refuse to send the webhook. However, the Response or anywhere else (except log on server) doesn't describe the reason, and may make user think that the webhook server is crashed.
This PR writes error message Hook delivery skipped as webhook is inactive. to Response Body, so that user can know the status clearly.

Comparison

Current behavior

Expected behavior

Closes #26824

[puni9869]

Thanks for your contribution, could you create an ISSUE for this pr, for a discussion to take this PR forward

[techknowlogick]

Thanks for this PR. Instead of adding content to the webhook response body, could you instead:

1. Disable the "Test Delivery" button
2. Add an on-hover tooltip to let users know that test deliveries are disabled
3. same for the "retry" webhook button
4. display an "error flash" if someone bypasses the disabled button and does an HTTP POST of the form

If you need any help, or pointers on where to start please comment here and we can help out :)

[Young-Lord]

Sorry, currently I have no time to finish a pr of such scale. The only thing I can do is to post some relative links so that others may implement all these features.
Also, I'm not clear about how should I show the error flash for a POST request.

gitea/web_src/js/features/comp/WebHookEditor.js

Line 32 in 45976a1

$('#test-delivery').on('click', function () {

gitea/templates/repo/settings/webhook/history.tmpl

Line 6 in 45976a1

<button class="ui teal tiny button" id="test-delivery" data-tooltip-content="{{.locale.Tr "repo.settings.webhook.test_delivery_desc"}}" data-link="{{.Link}}/test" data-redirect="{{.Link}}">{{.locale.Tr "repo.settings.webhook.test_delivery"}}</button>

[Young-Lord]

One more thing: Can we allow Test delivery even when Webhook is inactive? When debugging, this might be useful.

[yardenshoham]

Replaced by #27211