Add 'remove' button and method

New button that triggers `submitTag()` method directly (rather than throw onKeyDown event) and passes `null` as the newValue.  New `if` condition checks for null on newValue and if true, removes the tag that matches the originalValue.

This *does* currently delete all duplicate tags if they match the one you are deleting.  Not sure when you'd ever want duplicate tags, but regardless i'll likely switch this to work via Index, not value.

client/homebrew/editor/tagInput/tagInput.jsx

@@ -26,6 +26,11 @@ const TagInput = ({ unique = true, values = [], ...props }) => {
 
 	const submitTag = (newValue, originalValue) => {
 		setValueContext((prevContext) => {
+			// remove existing tag
+			if(newValue === null){
+				console.log('remove');
+				return [...prevContext].filter((context)=>context.value !== originalValue);
+			}
 			// add new tag
 			if(originalValue === null){
 				return [...prevContext, { value: newValue, editing: false }]
@@ -58,6 +63,7 @@ const TagInput = ({ unique = true, values = [], ...props }) => {
 				className='tag'
 				onClick={() => editTag(context.value)}>
 				{context.value}
+				<button onClick={(evt)=>{evt.stopPropagation(); submitTag(null, context.value)}}><i className='fa fa-times fa-fw'/></button>
 			</div>
 		);
 	};