Add support to Sentinel-1 from multiple sources

[rolfsimoes]

Describe the requested improvement Add support to additional Sentinel-1 collections

• [x] MPC Sentinel-1-RTC (https://planetarycomputer.microsoft.com/dataset/sentinel-1-rtc) - Requester pays
• [x] AWS Sentinel-1-GRD (https://registry.opendata.aws/sentinel-1/) - Requester pays
• [ ] DEAFRICA Sentinel-1-RTC (https://registry.opendata.aws/deafrica-sentinel-1/) - Open

Associated sits API function

• sits_cube()
• sits_regularize()

Additional context See implementation of MPC Sentinel-1-GRD.

[rolfsimoes]

AWS Sentinel-1-GRD does not support STAC API