fix(drawer): add MUI skeleton placeholders for politician drawer

[Almee98]

What github.com/wevote/WebApp/issues does this fix? WV-476

Summary

Adds MUI skeleton placeholders to the politician/candidate detail drawer (OrganizationModal) to keep layout stable and reduce layout shift while content loads.

Changes

New

• CardForListBodySkeleton: Skeleton component that mirrors CardForListBody layout using MUI Skeletons and CampaignCardStyles

OrganizationModal

• Replace Suspense fallbacks with Skeletons for ImageHandler, CampaignSupportThermometer, PoliticianCardForList, IssuesByBallotItemDisplayList

PoliticianCardForList

• Use CardForListBodySkeleton instead of CardForListBodyPlaceholder when loading

CardForListBody

• Replace Suspense fallbacks with Skeletons for OpenExternalWebSite, thermometer, office row, ItemActionBar
• Party row: always render; show skeleton when politicalParty is falsy
• Office row: add icon placeholder (18×18 in 25px wrapper) to Suspense fallback

CampaignSupportThermometer

• Reserve full layout while campaign data loads
• Fix flex layout for text skeletons (flex: 1, min-width: 0 on HeartDetailsWrapper)
• Skeleton height 18px to match line height

HeartFavoriteToggleLoader

• Outer Suspense fallback: 60×36 rounded skeleton

VoterPositionEntryAndDisplay

• ItemActionBar Suspense fallback: two 100×36 button skeletons

Future Work

To achieve a smoother transition from skeleton to loaded content, a larger refactor of the drawer’s data flow and loading architecture will be needed. I’d like to talk about this in our next meeting.

Testing

• Open the politician drawer from the ballot
• Confirm skeletons render with stable layout
• Verify reduced layout shift and flicker as content loads