Minor fixes

- 9 newly improved unit icons for the Grand Master unit
- New handmade icon for the Produce Grand Master skill
- Fixed icon for Cosmos Awakening
- Fixed Cosmos Awakening hero skill stack bonus exp being applied to all units (now only works for summoned & magic origin units)
- Star Dust hero skill now works for Summoned units and also Magic origin units
- Astral interlock now works for Summoned units and also Magic origin units
- Fixed texture for the Helmet of Grand Master units
- Mod size optimisation

[Astrologer path tiers I] Star dust skill cost point down to 2 (was 3)
[Astrologer path tiers I] Rework for Cosmos purity. Is now called Cosmos awakening, and will give the Quick learner ability to all summoned unit in the hero army.

- The city enchantment spell "Energy transmutation" cannot be stacked anymore on one single city.
Thank you to [FTJ] Otto for spotting the exploit.

- The skill "Unwavering invocations" will now provide the Antimagic cloak ability instead of the Vigilant ability; this is due to the bad synergy between Vigilant and the Teleport ability from the Cosmos Watcher (spoiler: the Watcher guards after using teleport, making you unable to get an attack after teleporting)

Quick fix regarding level & skill point costs for the core path skills.

Pretty big update with various improvements & the hero rework skill tree :

- For better compatibility with the other great mods out there (chivalrous intention, to not name it), Summon Fantastic creatures was put back and the Summon fantastic creature spell has its original file setup normally. The research "Summon Node Serpent" was just renamed "Summon Cosmos creatures" and will now unlock the Node serpent + the two other cosmos summon initially introduced by the mod.

- Astral shift is nerfed- instead of preventing a unit to act, it will now just reduce its physical damage to 1. This is due to the ease of access to the debuff through the new Hero upgrades which were not in the original mod.

- Displacement spell is slightly nerfed- the duration of Astral shift caused by the spell now last 1 turn only instead of 2.

- Some various nerfs on the Zodiac buffs- same reason as above. Most buffs giving a +3 stat upgrade now give +2 instead.

- Quite a lot of under-the-hood VFX improvements. Many abilities or spells belonging to one of the three paths had its VFX colour chart being harmonised for better visibility and logic. (arcanist -> purpleish; stormancer -> Grey-blueish; Astrologer -> yellow-Blueish). The VFX rework affects at the same time previous new unit or abilities and the new hero abilities.

- And finally, a large part of the update is about the hero skill tree rework, which you can see the full change list here: https://gtm.steamproxy.vip/workshop/filedetails/discussion/1849210970/3639496710963703518/

- Corrected texte for planetarium (casting symbol was missing)
- Corrected icon for frostling Grandmaster
- Removed a FMD Dictionnary file which was having identical ID with the Beholder unit, potentially creating crashes in certain circumstances

Fixed a missing link preventing Halfling Grand Master to be produced.

Changed the AI settings regarding the usage of the "Astral Guard" ability from the Cosmos Gardian.

The AI should now use this ability in a smarter way (was stupidly spamming it before)