SNOW-761744 Added URL Validator and URL Encoder

[sfc-gh-hchaturvedi]

Description

Added URL Validator to ensure that the SSO URL being used in external browser is valid. Also added URL Encoder to encode base64 strings to url safe format.

Checklist

• Code compiles correctly
• Run make fmt to fix inconsistent formats
• Run make lint to get lint errors and fix all of them
• Created tests which fail without the change (if possible)
• All tests passing
• Extended the README / documentation, if necessary

[github-actions]

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[sfc-gh-hchaturvedi]

I have read the CLA Document and I hereby sign the CLA

[sfc-gh-igarish]

LGTM

[sfc-gh-wshangguan]

So we just add some util functions without using them at this moment?