Change InlinePanel for MultipleChooserPanel

[AdalbertoMoz]

Description

This PR updates several Wagtail Panels from InlinePanel to MultipleChooserPanel, but only where feasible, as outlined in the original documentation.

Given that the 'Files changed' section might not fully capture the extent of these modifications, here is a list to assist testers in comparing the behavior between the Review App and other stable environments like Staging, ensuring the main functionality remains unaffected:

• network-api/networkapi/nav/models.py
  • NavMenu:
    • Featured Blog Topics
• network-api/networkapi/wagtailpages/pagemodels/app_install.py
  • AppInstallPage:
    • Donation Modal
• network-api/networkapi/wagtailpages/pagemodels/base.py
  • InitiativesPage:
    • Highlights
  • ParticipatePage2:
    • Highlights Group 1
    • Highlights Group 2
  • Homepage:
    • Areas of focus
    • News you can use
    • Spotlight
• network-api/networkapi/wagtailpages/pagemodels/blog/blog.py
  • BlogPage:
    • Author(s)
    • Related Blog Posts
• network-api/networkapi/wagtailpages/pagemodels/blog/blog_index.py
  • BlogIndexPage:
    • Featured
• network-api/networkapi/wagtailpages/pagemodels/buyersguide/article_page.py
  • BuyersGuideArticlePage:
    • Authors
    • Content categories
    • What to read next (related articles)
• network-api/networkapi/wagtailpages/pagemodels/buyersguide/campaign_page.py
  • BuyersGuideCampaignPage:
    • Donation Modal
• network-api/networkapi/wagtailpages/pagemodels/buyersguide/categories.py
  • BuyersGuideProductCategory:
    • Related articles
  • BuyersGuideCategoryNav:
    • Categories
• network-api/networkapi/wagtailpages/pagemodels/buyersguide/editorial_content_index.py
  • BuyersGuideEditorialContentIndexPage:
    • Popular articles
• network-api/networkapi/wagtailpages/pagemodels/buyersguide/homepage.py
  • BuyersGuidePage:
    • Supporting Pages
    • Popular articles
    • In the press
    • Excluded categories
• network-api/networkapi/wagtailpages/pagemodels/buyersguide/products.py
  • ProductPage:
    • Product Category
    • News Links
    • Related Products
    • Related Articles
• network-api/networkapi/wagtailpages/pagemodels/campaign_index.py
  • CampaignIndexPage:
    • Featured Pages
• network-api/networkapi/wagtailpages/pagemodels/campaigns.py
  • CampaignPage:
    • Donation Modal
• network-api/networkapi/wagtailpages/pagemodels/libraries/rcc/detail_page.py
  • RCCDetailPage:
    • Content types
    • Curricular areas
    • Topics
• network-api/networkapi/wagtailpages/pagemodels/libraries/rcc/landing_page.py
  • RCCLandingPage:
    • Featured content types
    • Featured authors
• network-api/networkapi/wagtailpages/pagemodels/libraries/research_hub/detail_page.py
  • ResearchDetailPage:
    • Topics
    • Regions
• network-api/networkapi/wagtailpages/pagemodels/libraries/research_hub/landing_page.py
  • ResearchLandingPage:
    • Featured topics
    • Featured authors
• network-api/networkapi/wagtailpages/pagemodels/publications/article.py
  • ArticlePage:
    • Author(s)
• network-api/networkapi/wagtailpages/pagemodels/publications/publication.py
  • PublicationPage:
    • Author(s)

Link to sample test page: https://foundation-s-feature-12-t4lbf6.herokuapp.com/en/
Related PRs/issues: #12421

Checklist

Tests
- [ ] Is the code I'm adding covered by tests?

Changes in Models:
- [ ] Did I update or add new fake data?
- [ ] Did I squash my migration?
- [ ] Are my changes backward-compatible. If not, did I schedule a deploy with the rest of the team?

Documentation:
- [ ] Is my code documented?
- [ ] Did I update the READMEs or wagtail documentation?

Merge Method
💡❗Remember to use squash merge when merging non-feature branches into main

┆Issue is synchronized with this Jira Story