Deprecate `compress_encoding` in sumologic exporter

[swiatekm]

compress_encoding is used for configuring compression, but this is already done by the confighttp helper from core, and works correctly as-is.

We should:

1. Deprecate compress_encoding and document using compression instead
2. Validate that we only accept compression options that Sumo supports
3. Remove compress_encoding and all of our own compression code for HTTP

[rnishtala-sumo]

@swiatekm-sumo I can close this issue as addressed as part of this PR and create a new one for the breaking changes in v0.94.0