Asset view extension point for top actions

[#1]

Request for Feature Enhancement (RFE) Summary:	When using UI Extensibility for the Asset view, when using UI Extensibility on the Asset view, the current options are rather limited and does not allow to cover all cases. Particularly features like "download asset" are basically impossible to override, since the button exists within the toolbar but also outside in the top bar
Use-case:	Asset View extensibility should provide an extension point for the top bar (the button list in the top right ) .  As an example of things that cannot be done right now is overriding the button for "download asset". It is possible to hide or override the behavior of the download button in browse view (since it appears in the quick actions and action bar), but that button also exists in the top bar in a place where no extension points exists, making overriding all cases impossible
Current/Experienced Behavior:	There is no possibility to extend or modify the action buttons at the top of the asset view (neither on browse or asset view)
Improved/Expected Behavior:	There should be a way to extend or modify the action buttons at the top of the asset view
Environment Details (AEM version/service pack, any other specifics if applicable):	N/A
Customer-name/Organization name:	Banking
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Code package (if applicable):