standardising buttons appearance

...es/rocketchat-authorization/client/views/permissions.html

...ocketchat-authorization/client/views/permissionsRole.html

...-mail-messages/client/views/mailMessagesInstructions.html

...etchat-channel-settings/client/views/channelSettings.html

packages/rocketchat-emoji-custom/admin/emojiEdit.html

packages/rocketchat-emoji-custom/admin/emojiInfo.html

packages/rocketchat-importer/client/admin/adminImport.html

.../rocketchat-importer/client/admin/adminImportPrepare.html

...tchat-integrations/client/views/integrationsIncoming.html

...tchat-integrations/client/views/integrationsOutgoing.html

packages/rocketchat-livechat/app/client/views/survey.html

...ketchat-livechat/client/views/app/livechatAppearance.html

...at-livechat/client/views/app/livechatCustomFieldForm.html

...hat-livechat/client/views/app/livechatDepartmentForm.html

...tchat-livechat/client/views/app/livechatIntegrations.html

...ocketchat-livechat/client/views/app/livechatTriggers.html

...s/rocketchat-livechat/client/views/app/livechatUsers.html

...ketchat-livechat/client/views/app/tabbar/visitorEdit.html

...chat-livechat/client/views/app/tabbar/visitorForward.html

...ketchat-livechat/client/views/app/tabbar/visitorInfo.html