feat: enable create root account under a network (#494)

* add network icon to legacy account

* refactor screen heading

* fix stylesheet creation

* remove protocol from AccountIcon

* add root account derivation

* enable derivation root from derivationPath screen

* add '//kusama' into test suites

* fix match and remove console.log

* flatten styles in screenHeadings

* change workflow

* move add network button to bottom

* revert the channge on AccountNetworkChooser.js