Allow dynamic filtering of actions available within an iteration

For now, actions can be filtered with conditions that use EL expressions.
For example:

<condition>#{lockActions.getCanLockDoc(document)}</condition>

These EL expressions are evaluated in a given ActionContext, that exposes variables such as currentDocument or currentPrincipal.
This is fine for actions that apply to the current document for example, such as Lock document, for which the condition only needs these "global" variables to be evaluated.
But we don't have any easy way to declare an action available for some or all items of a list, guarded by a condition that would be evaluated against each item of the list.
Typically in the case of Archived versions (see NXP-9118), we can now contribute actions available for each version, but cannot guard such actions by a condition depending on the version item.