[SDK-4335] Add passwordless authentication APIs

[ewanharris]

🔧 Changes

This implements the passwordless APIs on the authentication client:

• SendEmail
• LoginWithEmail
• SendSMS
• LoginWithSMS

📚 References

🔬 Testing

Covered by tests and test email manually. Currently testing SMS once I get twilio working

📝 Checklist

• All new/changed/fixed functionality is covered by tests (or N/A)
• I have added documentation for all new/changed functionality (or N/A)

[codecov-commenter]

Codecov Report

Patch coverage: 92.10% and project coverage change: -0.02 ⚠️

Comparison is base (ba79baa) 94.61% compared to head (6758e87) 94.60%.

Additional details and impacted files

@@            Coverage Diff             @@
##             beta     #229      +/-   ##
==========================================
- Coverage   94.61%   94.60%   -0.02%     
==========================================
  Files          43       44       +1     
  Lines        8098     8136      +38     
==========================================
+ Hits         7662     7697      +35     
- Misses        341      343       +2     
- Partials       95       96       +1     

Impacted Files	Coverage Δ
authentication/passwordless.go	91.89% <91.89%> (ø)
authentication/authentication.go	89.09% <100.00%> (+0.20%)	⬆️

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[Widcket]

LGTM