Replace underscore with lodash for ./app/assets/javascripts/lib

Replace all underscore methods with native javascript functions (when possible) or lodash equivalents within the directory listed in the title. If there are no equivalents, please start a conversation on the issue on how to best handle this case and get consensus before moving forward. Before submitting an MR, please make sure all specs pass after switching to use the new functions either in native javascript or lodash.