implement editable dataframe to manage dataframe editor component

[FabienArcellier]

import writer as wf


def on_record_add(state, payload):
	payload.record['sales'] = 0 # default value inside the dataframe
    state['df'].record_add(payload)
    
def on_record_change(state, payload):
    state['df'].record_update(payload)

def on_record_action(state, payload):
	"""
	This event corresponds to a quick action in the drop-down menu to the left of the dataframe.
	"""
	if payload.action == 'remove':
	    state['df'].record_remove(payload)
	if payload.action == 'important':
		state['df'].record(payload.id).update('flag', True) # update the column flag of the dataframe to true, trigger une mutation record_update
	if payload.action == 'open':
		state['record'] = state['df'].record(payload.id)

def on_record_select(state, payload):
	state['df_selected_record'] = payload['selected']

# trigger on button outside the dataframe editor
def on_save_click(state, payload):
    state['df'].df.to_csv('file.csv')


initial_state = ss.init_state({
    "df": wf.EditableDataframe(
	    df
	)
})


# snippets
state['df'].df # get the real dataframe datastructure
state['df'].df = df # set a new dataframe, send the entire dataframe
state['df'].record_update(payload) # update a record using frontend payload
state['df'].record_remove(payload) # remove a record using frontend payload
state['df'].record_add(payload) # add a new record using frontend payload

more in #63