Implement the initial Pairing user workflow and disconnect option for
the first session.
Also
- rename pairing modal accordingly (`PairWCModal.qml`) to make room for the proper
`ConnectDAppModal.qml`
- basic tests for service helpers
- update storybook to reflect the new user workflows
Closes#14607
Other changes
- start Wallet Connect SDK using web engine after wallet is ready
- source WC project ID from the constants in nim
- close list when opening the `ConnectDappModal`
- remove the old POC modal instantiation
- rename ConnectDappPopup to Modal for consistency
- move specific dapps related user settings to their place in the component
- add DAppsStore to be used for dapps abstraction
Updates #14556