fix: hide new library button for ineligible users split studio view (#35316)

[kaustavb12]

Description

(cherry picked from commit 79fb1cc)

Cherry Pick of #35316

This PR does the following:

1. The New Library button is now only shown to eligible users in the split studio view, instead of all active users.
2. Common code between user_can_view_create_library_button() and user_can_create_library() functions are refactored out to a new fuction.

Testing instructions

Check #35316

Other information

Private Ref: BB-9077

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Thanks for the pull request, @kaustavb12!

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[0x29a]

👍

• I tested this in combination with the frontend part. Non-staff user wasn't able to see the New Library button, while staff users were.
• I read through the code