Bug 1601093, Rename the remaining .xul files to .xhtml in toolkit/ r=marionette-reviewers,mossop,whimboo

Differential Revision: https://phabricator.services.mozilla.com/D55857

--HG--
rename : toolkit/components/alerts/resources/content/alert.xul => toolkit/components/alerts/resources/content/alert.xhtml
rename : toolkit/components/apppicker/content/appPicker.xul => toolkit/components/apppicker/content/appPicker.xhtml
rename : toolkit/components/extensions/dummy.xul => toolkit/components/extensions/dummy.xhtml
rename : toolkit/components/passwordmgr/content/passwordManager.xul => toolkit/components/passwordmgr/content/passwordManager.xhtml
rename : toolkit/components/printing/content/printPageSetup.xul => toolkit/components/printing/content/printPageSetup.xhtml
rename : toolkit/components/printing/content/printPreviewProgress.xul => toolkit/components/printing/content/printPreviewProgress.xhtml
rename : toolkit/components/printing/content/printProgress.xul => toolkit/components/printing/content/printProgress.xhtml
rename : toolkit/components/prompts/content/commonDialog.xul => toolkit/components/prompts/content/commonDialog.xhtml
rename : toolkit/components/prompts/content/selectDialog.xul => toolkit/components/prompts/content/selectDialog.xhtml
rename : toolkit/components/viewconfig/content/config.xul => toolkit/components/viewconfig/content/config.xhtml
rename : toolkit/content/editMenuKeys.inc.xul => toolkit/content/editMenuKeys.inc.xhtml
rename : toolkit/content/resetProfile.xul => toolkit/content/resetProfile.xhtml
rename : toolkit/content/resetProfileProgress.xul => toolkit/content/resetProfileProgress.xhtml
rename : toolkit/modules/win.xul => toolkit/modules/win.xhtml
rename : toolkit/profile/content/createProfileWizard.xul => toolkit/profile/content/createProfileWizard.xhtml
rename : toolkit/profile/content/profileDowngrade.xul => toolkit/profile/content/profileDowngrade.xhtml
rename : toolkit/profile/content/profileSelection.xul => toolkit/profile/content/profileSelection.xhtml
extra : moz-landing-system : lando