Create "Explore/Library" Sidepanel Form for new channel and category browsing

[marcellamaki]

Overview:
The new category browse and search is a way for users to find content that is relevant to their needs and interests. The side panel presents a variety of filter options that allow users to search by our metadata like the activity type, the category, level, etc.

Design context/User stories:

• Find something at my level that's extracurricular or supplementary
• Find something new and different that I can do without a teacher or prerequisite knowledge
• Find something fun and interesting

Done when:

• The side panel opens and presents the full form of filtering options
• Selecting options from the sidebar successfully filters results
• Filtering occurs with each subsequent selection in the form, rather than making a series of selections and having a "submit" event
• Selecting from the "All Categories" filter opens a "categories" modal that presents the complete list of category filter options in accordance with our new metadata categorization architecture
• A user can see the panel without any filters selected, or arrive on the page with some filters already in place
• Side panel is responsive in accordance with figma designs

Outside of scope:

• Updating the results page to have the new cards

Figma References

[marcellamaki]

Closed with #8548