Fixes kafka consume excepiton for GroupLoadInProress errcode (dotnetc…

…ore#1085)

* Fixes and add options of kafka consume excepiton for GroupLoadInProress errcode.  dotnetcore#1084

* clean code

* Add kafka consume exception logs.

Fixed Activity is created as null when ASP.NET Core instrument is not…

… enabled.

Fixes RabbitMQ federation plugin, some headers with object values cau…

…se cast exceptions. (dotnetcore#1036)

Use KeyExistsAsync for exists check (dotnetcore#1004)

Update docs.

Fixed consumer register cancellation token source null referencee bug. (

dotnetcore#952)

Merge pull request dotnetcore#936 from dotnetcore/supports/flow-control

Improve flow control for message of in memory

Add docs path filter for github action.

Update version.props

DiagnosticObserver does not use null connection (dotnetcore#845)

* DiagnosticObserver does not use null connection

* Make TryGetSqlConnection static.

Co-authored-by: Dave Smith <dave.smith@ventivtech.com>