1.17 Loyalist sprite updates

[doofus-01]

Updating the Loyalist Sprites from this thread:
https://forums.wesnoth.org/viewtopic.php?t=34095

Swordsman attack animation is from:
https://forums.wesnoth.org/viewtopic.php?p=595151#p595151

Some of the old sprites have decent animations, but I'm not going to try to replace all of the existing frames. Defense + attack need to be done to be considered "complete", the idle/death/etc. are nice to have but not strictly needed.

EDIT: This PR got bigger than what I intended when I opened it. I'll cull this list, there will be a followup.

• Swordsman - Mostly done, lost the idle animation
• Pikeman - Basic combat animations done. Lost the idle and die animations.
• Royal Guard -Base image, defense & attack animations done. No death/idle animations to lose.
• Halberdier - base image, defend & attack animations done. Lost the idle animation
• Lieutenant - most important animations done, lost the idle animation
  Javelineer - base image to work from exists, not touched yet.
  General - nothing done yet
  Grand Marshal - nothing done yet
• Sergeant - most important animations done, lost the idle animation

Note to self: Add "Luke Bunday (Amorphous)" to the credits, for the swordsman slashing animation.

[knyghtmare]

General - nothing done yet

This was supposed to be the general, but since no updates for ~10 years, Vyncyn modified it to suit his era's faction, but yeah...there is something.

And here you go, more resource material: https://github.com/Turuk/wesnoth-resources/tree/master/units/loyalists

Spearman is there but also is not present in the list.