Improve styling of Search view and Search filters:

• Adjust offset margins to the rest of the UI views within the app;
• Add font-weight 700 to Search button and increase font-size of icons within buttons;
• Add a caret pointing up in the border-top when filters are displayed;
• Add font-weight for labels (700);
• Review spacing and font-size for Content-type dropdown;
• Update Custom range modal based on defined Ui standards for modals already implemented in the UI (center alignment & bolded font-weight for primary action).