client/service: refactor group param of spawn into an Enum (#10248)

* refractored group param to enum

* refractored group param to enum

* changed group param to GroupName enum for other methods too such as spawn_inner
updated docs

* revert on task type

* put back ticks in GroupName

* Update client/service/src/task_manager/mod.rs

Co-authored-by: Bastian Köcher <[email protected]>

* document group name
change specific to actual in enum declaration

* change documentation

* Update client/service/src/task_manager/mod.rs

Co-authored-by: Andronik Ordian <[email protected]>

* changed Actual to Specific

* Update client/service/src/task_manager/mod.rs

Co-authored-by: Andronik Ordian <[email protected]>

* Update client/service/src/task_manager/mod.rs

Co-authored-by: Bastian Köcher <[email protected]>

* Update client/service/src/task_manager/mod.rs

Co-authored-by: Bastian Köcher <[email protected]>

* Update client/service/src/task_manager/mod.rs

Co-authored-by: Bastian Köcher <[email protected]>

Co-authored-by: Damilare <[email protected]>
Co-authored-by: Bastian Köcher <[email protected]>
Co-authored-by: Andronik Ordian <[email protected]>