Support more TLS/SSL certificate providers in http source

[chenqi0805]

Is your feature request related to a problem? Please describe.
Currently only local file certificate provider is supported.

Describe the solution you'd like
We will expand support to s3 and ACM when necessary

Describe alternatives you've considered (Optional)
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.

[dlvenable]

This task is highly related to #364. I'd like us to centralize this feature using plugins.