Dwarvish Thunderer alternative advancement idea

Describe the desired feature

Hi! I was prompted to prepare this topic by the idea of adding a new alternative LV2 branch promotion for the Dwarvish Thunderer.

The unit and its graphics were met with positive feedback from SP lead Dalas and the Wesnoth community. I am looking forward to the opinion on the topic from Art Director doofus-01.

attack animation

bob animation

idle animation

https://github.com/user-attachments/assets/a76d3fe8-a063-4b53-8ec0-d6b36725889c

ZIP folder with the unit's sprites and its .cfg file.

Dwarvish_Torchbeard.zip

@doofus-01 @Dalas121