add "open for triage" to project context menu

[psifertex]

The current context-menu when right-clicking a file in a project is:

We should add "open for triage" which is especially useful for either malware or firmware where you don't want most analysis to run

[negasora]

This is tricky because triage is a plugin that has no exposed way to open files given names - the "file open mode" that's registered just opens a file picker tree