feat: Run PreValidate hooks for check cmd (#437)

PreValidate can be used to mount remote directories (e.g. via NFS) so
they must executed first before running any restic commands.

This was done for the backup command in 13aa560, but not for check. This
commit fixes that.

internal/config.go

@@ -188,15 +188,31 @@ func CheckConfig() error {
 	if !CheckIfResticIsCallable() {
 		return fmt.Errorf(`%s was not found. Install either with "autorestic install" or manually`, flags.RESTIC_BIN)
 	}
-	for name, backend := range c.Backends {
-		backend.name = name
-		if err := backend.validate(); err != nil {
+
+	cwd, _ := GetPathRelativeToConfig(".")
+	for name, location := range c.Locations {
+		location.name = name
+
+		// Hooks before location validation
+		options := ExecuteOptions{
+			Command: "bash",
+			Dir:     cwd,
+			Envs: map[string]string{
+				"AUTORESTIC_LOCATION": location.name,
+			},
+		}
+		if err := location.ExecuteHooks(location.Hooks.PreValidate, options); err != nil {
+			return err
+		}
+
+		if err := location.validate(); err != nil {
 			return err
 		}
 	}
-	for name, location := range c.Locations {
-		location.name = name
-		if err := location.validate(); err != nil {
+
+	for name, backend := range c.Backends {
+		backend.name = name
+		if err := backend.validate(); err != nil {
 			return err
 		}
 	}