User password change (#280)

* start passwordChangeHandler

* add user scope

* add user module / api path

* add password change request

* make comment clearer

* add user to processor

* required true

* add processor call to handler

* don't pass tc or channel

* change password func + tests

* add some first docs about password management

* update swagger docs

* add api tests

* go fmt

* test fixes

internal/processing/user.go

@@ -0,0 +1,31 @@
+/*
+   GoToSocial
+   Copyright (C) 2021 GoToSocial Authors admin@gotosocial.org
+
+   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 processing
+
+import (
+	"context"
+
+	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+	"github.com/superseriousbusiness/gotosocial/internal/oauth"
+)
+
+func (p *processor) UserChangePassword(ctx context.Context, authed *oauth.Auth, form *apimodel.PasswordChangeRequest) gtserror.WithCode {
+	return p.userProcessor.ChangePassword(ctx, authed.User, form.OldPassword, form.NewPassword)
+}