feat(demo): add spinner component

[jboix]

Description

Closes #82

Introduces a SpinnerComponent that can be dynamically attached to a DOM element and can be shown or hide on command.

This spinner offers a visual cue to signify that content is being loaded or processed during user interactions or asynchronous operations. It has been added to the following pages :

• Search : The spinner is shown whenever a search is launched.
• Lists: The spinner is shown when a section is opened.

Changes

• The search page is now a class.
• Performing a new search will abort the previous request if it's ongoing.

[github-actions[bot]]

Coverage report

St.:grey_question:	Category	Percentage	Covered / Total
🟢	Statements	98.36%	481/489
🟢	Branches	93.42%	227/243
🟢	Functions	100%	137/137
🟢	Lines	99.15%	464/468

Test suite run success

142 tests passing in 9 suites.

Report generated by 🧪jest coverage report action from d5ab24ebdfe4eb7058104f025e13059fa959006e