Allow the option to use an arbitrary application version as a template when adding a new version
When adding a new version of an existing application to the catalog, always the version that has been added last is used as a template.
Then new version wizard has its fields populated with the values from the previously added version. While this is convenient and speeds up the new version addition process, it should be improved to better accommodate applications with multiple versions that are maintained in parallel. For this reason, it should be possible to specify an arbitrary existing version as a base template when adding a new version of an application.
For example, Grafana in parallel maintains v9 and v10. If we assume that the latest version uploaded to the catalog is v10.0.1 (chart version v7.0.0) and then we want to upload a new version of v9, e.g. v9.1.0, it should be possible to use the spec for the previous v9 version as a base, instead of the spec for v10.0.1