[feature] Implement explicit domain allows + allowlist federation mode (#2200)

* love like winter! wohoah, wohoah

* domain allow side effects

* tests! logging! unallow!

* document federation modes

* linty linterson

* test

* further adventures in documentation

* finish up domain block documentation (i think)

* change wording a wee little bit

* docs, example

* consolidate shared domainPermission code

* call mode once

* fetch federation mode within domain blocked func

* read domain perm import in streaming manner

* don't use pointer to slice for domain perms

* don't bother copying blocks + allows before deleting

* admonish!

* change wording just a scooch

* update docs

internal/api/client/admin/domainallowdelete.go

@@ -0,0 +1,72 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package admin
+
+import (
+	"github.com/gin-gonic/gin"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+)
+
+// DomainAllowDELETEHandler swagger:operation DELETE /api/v1/admin/domain_allows/{id} domainAllowDelete
+//
+// Delete domain allow with the given ID.
+//
+//	---
+//	tags:
+//	- admin
+//
+//	produces:
+//	- application/json
+//
+//	parameters:
+//	-
+//		name: id
+//		type: string
+//		description: The id of the domain allow.
+//		in: path
+//		required: true
+//
+//	security:
+//	- OAuth2 Bearer:
+//		- admin
+//
+//	responses:
+//		'200':
+//			description: The domain allow that was just deleted.
+//			schema:
+//				"$ref": "#/definitions/domainPermission"
+//		'400':
+//			description: bad request
+//		'401':
+//			description: unauthorized
+//		'403':
+//			description: forbidden
+//		'404':
+//			description: not found
+//		'406':
+//			description: not acceptable
+//		'409':
+//			description: >-
+//				Conflict: There is already an admin action running that conflicts with this action.
+//				Check the error message in the response body for more information. This is a temporary
+//				error; it should be possible to process this action if you try again in a bit.
+//		'500':
+//			description: internal server error
+func (m *Module) DomainAllowDELETEHandler(c *gin.Context) {
+	m.deleteDomainPermission(c, gtsmodel.DomainPermissionAllow)
+}