dnd5e: Revisit Actions tab now that activities exist

[kgar]

Now that action economy is represented in an item's activities, the Actions tab is currently presenting UI based on the primary activity (i.e., the first activity).

Consider how the actions tab could be make more useful, such as being Activity-oriented instead of Item-Oriented. Then, when clicking the roll button for a given row in the actions list, the Activity that is represented is used, instead of the owning item.

In this setup, if a single item has numerous activities which are relevant to different sections of the Actions tab, all activities can be seen when a particular action type is needed most.

[kgar]

Also, review and resolve deprecations, if they still exist:

• [ ] item.system.save.ability replaced with ctx.save.ability
• [ ] item.system.save.dc replaced with ctx.save.dc.value

[kgar]

When revisiting how to represent damage rolls, pursue activity.getDamageConfig() for each activity. It provides damage parts and types.

Sample schema (varies):

{
    "scaling": 0,
    "rolls": [
        {
            "data": { /* there's a lot of data in here */},
            "parts": [
                "2d8"
            ],
            "options": {
                "type": "radiant",
                "types": [
                    "radiant"
                ],
                "properties": [
                    "mgc"
                ]
            }
        }
    ],
    "critical": {
        "allow": false
    }
}