Allow adding a new Entity tab through dynamic plugin configuration

[davidfestal]

Provide a clear and concise description of the feature request

Currently it is only possible to wire, through configuraion, some frontend dynamic plugin to an available mountpoint, and the plugin content will appear in the corresponding entity tab.
But it is not possible, through configuration, to add a new tab that would contain the dynamic plugin content.

Describe the problem that this feature resolves

It should be possible to do add the content of a dynamic plugin in a new tab, though it is obviously not recommended to add too many tabs (or one tab per plugin).

Additional context or screenshots for the feature request

Related PRs that should in fact be tackle with the general mechanism proposed here:

• Add a new tab to the EntityPage for the Quarkus console #1154
• feat(kiali): add kiali dynamic plugin #902

Acceptance Criteria

[davidfestal]

cc @christophe-f about what we discussed today.