Bug 1824612 - Convert consumers of toolkit/components/extensions to ES...

Bug 1824612 - Convert consumers of toolkit/components/extensions to ES modules. r=robwu,webcompat-reviewers,geckoview-reviewers,settings-reviewers,application-update-reviewers,credential-management-reviewers,devtools-reviewers,cookie-reviewers,twisniewski,sgalich,valentin,nalexander,mconley,m_kato

Depends on D175553

Differential Revision: https://phabricator.services.mozilla.com/D176005