sumologicexporter: use Sumo Logic Extension for authentication and to obtain endpoint

[sumo-drosiek]

Description:

Use Sumo Logic Extension for authentication and to obtain the endpoint. This is part of #31479 to make #32315 smaller, therefore it may have some unused code (like getSignalURL). Also OTLP format is not supported yet for neither of the formats

It also partially fixes #32375 (partially because as long as there is no a otlp support, data won't be pushed to Sumo Logic)

Link to tracking Issue: #31479

Testing:

• unit tests
• manual tests

Documentation:

• ensures that Sumo Logic Extension documentation is valid

[sumo-drosiek]

This PR adds functionality which doesn't work as is dedicated for OTLP format, but next PRs I'm going to add the following (if possible to split them):

• traces support (otlp)
• move logs signal from our repo
• move metrics signal from our repo
• another features (e.g. sticky session)

[sumo-drosiek]

cc: @astencel-sumo @swiatekm-sumo

[swiatekm]

LGTM, one minor nitpick.