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/fixture_test.go

@@ -9,20 +9,21 @@ import (
 	"path/filepath"
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/util"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestFixtureGeneration(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	test := func(gen func() (string, error), name string) {
 		expected, err := gen()
 		if !assert.NoError(t, err) {
 			return
 		}
-		bytes, err := ioutil.ReadFile(filepath.Join(fixturesDir, name+".yml"))
+		bytes, err := ioutil.ReadFile(filepath.Join(db.FixturesDir(), name+".yml"))
 		if !assert.NoError(t, err) {
 			return
 		}