@W-15200182@ PWA Kit V2 Hybrid session handling - WIP

[vcua-mobify]

This PR ports the approach taken in #1696 to reduce the amount of sessions that are churned as a shopper navigates between PWA v2 and SFRA.

These changes require the plugin_slas changes added in https://github.com/SalesforceCommerceCloud/plugin_slas/pull/187 to work

DONE
Single tab cases

• no more constantly regenerating the dwsid as a shopper jumps between SFRA/PWA
  a benefit of this is the tracking consent form no longer appears on each PWA -> SFRA transition since the user selection is remembered because we've kept the same dwsid
• logging in on PWA / SFRA logs you in on the other (ie. log in via SFRA checkout logs you into PWA also)
• logging out of one system logs you out of the other

Multi tab cases

• handle login on multi tab - a log in on one tab should log you in on other tabs
• handling logout on multi tab - a log out on one tab should log you out of other tabs
• updating PWA headers on multi tab auth change

TODO
Multi tab cases

• Make the update snappier. It should happen in the background rather than when user hovers over the header
• CSRF token errors on SFRA forms when session changes

AKA - we need a v2 version of #1703 to handle re-rendering PWA if SFRA changes the access token (which is in cookie store not local store)

Notes:
On SFRA, login state updates once the tab navigates to a new page. If a form is on the current SFRA page, we cannot do anything about that form's CSRF token being invalidated by a session change in a different tab.

• The main affected forms are the tracking consent form and checkout when a PWA login occurs
• Persisting the same DWSID through login is probably the way to keep these forms valid.