how to include import com.adobe.cq.forms.core.components.internal.models.v1.form to the cloud project

In general all models/classes located under internal package are not exported by Core (Forms) Components bundles. This means you cannot use them directly, this is done by design.

In other words the way how you implementation is done is incorrect, this is why the issue occurs. The proper way to extend Core Components model is to use delegation pattern.

Here you can find some information with examples:
https://github.com/adobe/aem-core-wcm-components/wiki/Delegation-Pattern-for-Sling-Models
https://experienceleague.adobe.com/docs/experience-manager-core-components/using/developing/customizing.html?lang=en#customizing-the-logic-of-a-core-component

Community Discussion Threads:
https://experienceleaguecommunities.adobe.com/t5/adobe-experience-manager/com-adobe-cq-wcm-core-components-internal-cannot-be-resolved/m-p/555795
https://experienceleaguecommunities.adobe.com/t5/adobe-experience-manager/extending-core-components/m-p/377916