LPS-44098 Adapt file entry context actions menu to DisplayContext

For Brian:

===================

Hi Brian:

Please take a look at commit 2653bae in this pull request because I have renamed FileEntryDisplayContext to DLActionsDisplayContext (and their associated Helpers). I made this decision because the class just models the state of the available actions in DM, not the state of a FileEntry. In fact, several variables are tested (fileEntry, fileVersion, the configuration of the portal) to determine if some buttons can be shown, or if they are enabled/disabled. This is, IMO, enough to show that the class is not only related to a FileEntry, but to something broader (in this case, the DM actions).

Hope you like it.

Best regards,
Ivan

===================