Refactor SessionServiceController to reuse some of the SessionServiceRequestHandler methods.

[forus]

Proposed here:
#10829 (comment)

SessionServiceRequestHandler is an HTTP client that talks to the session service. It has all low-level HTTP code to interact with the session service. SessionServiceController is doing the same now.

We can make SessionServiceController to call SessionServiceRequestHandler instead of composing low-level HTTP calls by itself.
See PublicVirtualStudiesController as an example

[Mehdi-17]

Hello @forus , can I work on this issue if no one else is?

[forus]

Hello @forus , can I work on this issue if no one else is?

@Mehdi-17 Hello, sure. Please go ahead. Thank you!

[Mehdi-17]

@forus thank you !!

[darkhanzhursin]

Hi @forus @Mehdi-17 what is the status of this issue?