Move My sources into a separate item in the menu

Please move the My sources section (currently under Data catalog) into a separate tab on the left navbar.

Changes:

• Remove tabs "Explore" and "My sources" in Data catalog

• Create a new tab on the left navbar, which will lead to My sources page

• Choose an icon for My sources - "File Folder"

Designs:

https://www.figma.com/file/xYebkVqwHssFJnOBG2LlCR/Wrangler?type=design&node-id=6562-341505&t=6PhjMkrHSXn1xVo1-4

Acceptance criteria:

• My sources page have separate page and item in the wrangler menu

• Remove Tabs view from Data Catalog page

• Move code from submodules (source submodule) to modules

• Fix selenium tests

• JS tests