[performance] Speed up some of the slower db queries (#523)

* remove unnecessary LOWER() db calls

* warn during slow db queries

* use bundb built-in exists function

* add db block test

* update account block query

* add domain block db test

* optimize domain block query

* fix implementing wrong test

* exclude most columns when checking block

* go fmt

* remote more unnecessary use of LOWER()

internal/db/bundb/domain_test.go

@@ -0,0 +1,57 @@
+/*
+   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 bundb_test
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/suite"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+)
+
+type DomainTestSuite struct {
+	BunDBStandardTestSuite
+}
+
+func (suite *DomainTestSuite) TestIsDomainBlocked() {
+	ctx := context.Background()
+
+	domainBlock := &gtsmodel.DomainBlock{
+		ID:                 "01G204214Y9TNJEBX39C7G88SW",
+		Domain:             "some.bad.apples",
+		CreatedByAccountID: suite.testAccounts["admin_account"].ID,
+	}
+
+	// no domain block exists for the given domain yet
+	blocked, err := suite.db.IsDomainBlocked(ctx, domainBlock.Domain)
+	suite.NoError(err)
+	suite.False(blocked)
+
+	suite.db.Put(ctx, domainBlock)
+
+	// domain block now exists
+	blocked, err = suite.db.IsDomainBlocked(ctx, domainBlock.Domain)
+	suite.NoError(err)
+	suite.True(blocked)
+}
+
+func TestDomainTestSuite(t *testing.T) {
+	suite.Run(t, new(DomainTestSuite))
+}