chore: enable forcetypeassert linter, fix issues (#38804)

Enable [`forcetypeassert`](https://github.com/gostaticanalysis/forcetypeassert)
linter to prevent unchecked type assertions. ~650 issues fixed, most
fixes were clean, some use `setting.PanicInDevOrTesting`.

The only behaviour changes are where code would previously send a 500 error
or panic, a 4xx error is now emitted.

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

routers/web/shared/label/label.go

@@ -11,7 +11,7 @@ import (
 )
 
 func GetLabelEditForm(ctx *context.Context) *forms.CreateLabelForm {
-	form := web.GetForm(ctx).(*forms.CreateLabelForm)
+	form := web.GetForm[*forms.CreateLabelForm](ctx)
 	if ctx.HasError() {
 		ctx.JSONError(ctx.GetErrMsg())
 		return nil