v1.0.10

Json upload mode (#21)

* Refactor parameter collection to ignore upload mode and add upload mode retrieval function

* Remove upload mode handling from parameter collection and related functions

* Add base64 download handler and refactor existing download functions

* Add error handling test for PlainDownloadHandler and implement StoreRawForTesting method

* Add tests for PlainDownloadHandler with base64 decoding scenarios

* Enhance base64 decoding in download handler and update HTML documentation for advanced mode

* Update README to include base64 encoding option for data retrieval

* Update README to clarify key pair usage and enhance feature descriptions