PanelWidgets Icons are unintuitive; update icons and/or add tooltips

[ahuang11]

Initially, I thought checkmark == annotator.commit but it's actually add_annotation; the triangle is actually commit.

I haven't looked closely at the code, but if they're tabler icons, I suggest using one of these upload icons, and also perhaps add a tooltip icon next to them.

import pandas as pd
import holoviews as hv
from holonote.annotate import Annotator, SQLiteDB
from holonote.app import PanelWidgets
import geoviews as gv
import panel as pn

gv.extension("bokeh")


conn = SQLiteDB(filename=":memory:")
annotator = Annotator(
    {"x": int},
    fields=["description"],
    connector=conn,
)

widgets = PanelWidgets(annotator)
df = pd.DataFrame([[1, 2], [3, 4], [5, 6]], columns=["x", "y"])

pn.Row(
    pn.Row(widgets, pn.indicators.TooltipIcon(value="Check == adds description")),
    hv.Curve(df, kdims=["x"], vdims=["y"]) * annotator,
)

[ahuang11]

This might be implemented on the Bokeh level.

[hoxbro]

I have added a description to the buttons in #54 for now to soften the unintuitiveness