Modify public api to simplify code

[marcosholgado]

Task/Issue URL: https://app.asana.com/0/488551667048375/1205984446323518/f

Description

This PR changes the messaging public API

Steps to test this PR

See task

[marcosholgado]

Current dependencies on/for this PR:

• develop
  • PR Integrate FE for purchasing a sub #3895
    • PR Modify public api to simplify code #3903 👈
      • PR Add welcome screen #3915
        • PR Add restore option #3918
          • PR Modify toolbar for subs #3932
            • PR Link email account with subs on create account #3938
              • PR Move CheckListItem to common-ui #3947
                • PR Adds NetP setting to new section in settings #3950
                  • PR Second iteration for settings #3956
                  • PR Add subs info in settings screen #3962
          • PR Add features to subs #3920

This stack of pull requests is managed by Graphite.

[aitorvs]

LGTM