enhancement: support for channeled actions & BLU unique damage actions

[xiashtra]

BLU has two channeled actions, Phantom Flurry and Apokalypsis which have several non-standard properties:

• These actions use the physical damage formula despite being magical actions, while still using the normal intelligence mainstat and spell speed stat modifiers like a standard magical action.
• Both are channeled actions similar to MCH Flame Thrower. They act as DoT actions with a 1s tick rate (instead of the standard 3s), with an additional immediate tick on use (i.e., Phantom Flurry channels for 5s, for a total of 6 ticks). They follow standard DoT snapshotting rules.
• As channeled actions, they block all other actions while being channeled (including auto-attacks).
• They are not canceled by Waning Nocturne, and will continue to channel for the full duration as long as they are started before Waning Nocturne applies.

Currently, I have worked around points 2, 3, & 4 by simulating these actions as DoTs with an artificially long duration (to simulate the correct number of ticks), and by manually advancing the cycle processor (with autos disabled) to simulate blocking other actions/auto-attacks. I do not currently have a way of forcing them to use the physical formula for damage calculations.

If possible, it would be nice to have proper channeled action support, and a way to override the caster vs physical damage formula in some way for a specific action.