refactor webhook *EditPost

[oliverpool]

Following #20729 this PR aims at reducing duplicated code in the *HooksEditPost functions.

I also moved the functions around, so that webhook types are grouped together, which makes it easier to read.

For instance the matrix endpoints is now simply (notice that fmt.Sprintf is not duplicated anymore!):

// MatrixHooksNewPost response for creating Matrix webhook
func MatrixHooksNewPost(ctx *context.Context) {
	createWebhook(ctx, matrixHookParams(ctx))
}

// MatrixHooksEditPost response for editing Matrix webhook
func MatrixHooksEditPost(ctx *context.Context) {
	editWebhook(ctx, matrixHookParams(ctx))
}

func matrixHookParams(ctx *context.Context) webhookParams {
	form := web.GetForm(ctx).(*forms.NewMatrixHookForm)

	return webhookParams{
		URL:         fmt.Sprintf("%s/_matrix/client/r0/rooms/%s/send/m.room.message", form.HomeserverURL, url.PathEscape(form.RoomID)),
		ContentType: webhook.ContentTypeJSON,
		HTTPMethod:  http.MethodPut,
		WebhookForm: form.WebhookForm,
		Type:        webhook.MATRIX,
		Meta: &webhook_service.MatrixMeta{
			HomeserverURL: form.HomeserverURL,
			Room:          form.RoomID,
			AccessToken:   form.AccessToken,
			MessageType:   form.MessageType,
		},
	}
}

[delvh]

Certainly looks far cleaner from what I can see.

[zeripath]

I think there's more that can be done here with a register block.

But this is still a good improvement.

[KN4CK3R]

make L-G-T-M work

[techknowlogick]

Ping lg-tm bot