[feature] Add opt-in RSS feed for account's latest Public posts (#897)

* start adding rss functionality

* add gorilla/feeds dependency

* first bash at building rss feed
still needs work, this is an interim commit

* tidy up a bit

* add publicOnly option to GetAccountLastPosted

* implement rss endpoint

* fix test

* add initial user docs for rss

* update rss logo

* docs update

* add rssFeed to frontend

* feed -> feed.rss

* enableRSS

* increase rss logo size a lil bit

* add rss toggle

* move emojify to text package

* fiddle with rss feed formatting

* add Text field to test statuses

* move status to rss item to typeconverter

* update bun schema for enablerss

* simplify 304 checking

* assume account not rss

* update tests

* update swagger docs

* allow more characters in title, trim nicer

* update last posted to be more consistent

internal/db/bundb/migrations/20221006114842_add_rss_functionality.go

@@ -0,0 +1,46 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2022 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 migrations
+
+import (
+	"context"
+	"strings"
+
+	"github.com/uptrace/bun"
+)
+
+func init() {
+	up := func(ctx context.Context, db *bun.DB) error {
+		_, err := db.ExecContext(ctx, "ALTER TABLE ? ADD COLUMN ? BOOLEAN DEFAULT false", bun.Ident("accounts"), bun.Ident("enable_rss"))
+		if err != nil && !(strings.Contains(err.Error(), "already exists") || strings.Contains(err.Error(), "duplicate column name") || strings.Contains(err.Error(), "SQLSTATE 42701")) {
+			return err
+		}
+		return nil
+	}
+
+	down := func(ctx context.Context, db *bun.DB) error {
+		return db.RunInTx(ctx, nil, func(ctx context.Context, tx bun.Tx) error {
+			return nil
+		})
+	}
+
+	if err := Migrations.Register(up, down); err != nil {
+		panic(err)
+	}
+}