[EPIC] Improve Kiota VS Code extension UI

[maisarissi]

Challenge

With the grow in usage in Kiota and new features added, our current UI is becoming overwhelming for users, with a lot of icons and actions.
Because we do show all icons for each endpoint/operation, we are running out of scope when thinking in new features we are working to add (like http snippets).

Proposal

We need to do incremental and several small changes in the UI to make it more clear and provide the best value to users, only showing the specific actions they can perform.

Tasks

• Kiota Workspace panel should list all clients and plugins available in the current VS code workspace #5715
• TreeView icons are still using the "no entry" icon compared to the design #5219
• The "Edit Paths" option in the code lense should be renamed to "Select" #5216
• Show "Generate" or "Regenerate" button in the API Explorer based on the user flow #5800
• Change add and remove icons and their actions in the API Explorer
• Explorer using secondary side bar