Move db related basic functions to models/db (#17075)

* Move db related basic functions to models/db

* Fix lint

* Fix lint

* Fix test

* Fix lint

* Fix lint

* revert unnecessary change

* Fix test

* Fix wrong replace string

* Use *Context

* Correct committer spelling and fix wrong replaced words

Co-authored-by: zeripath <art27@cantab.net>

models/main_test.go

@@ -7,15 +7,17 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
+
 	"github.com/stretchr/testify/assert"
 )
 
 // TestFixturesAreConsistent assert that test fixtures are consistent
 func TestFixturesAreConsistent(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	CheckConsistencyForAll(t)
 }
 
 func TestMain(m *testing.M) {
-	MainTest(m, "..")
+	db.MainTest(m, "..")
 }