feat: add single sign on feature using SAML

[RawanMatar89]

Describtion:

added new button in sign in view named "Sign in with SSO" to be use for opening single sign on web view

Screenshots:

Before	After
e.g. when tap on "Sign in with SSO"

TODO:

• [ ] Rebase and remove the RTL commit
• [ ] Fix unit tests
• [ ] Get a full review

[openedx-webhooks]

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