some columns do not appear in hover if using labels overrides already used common names in Plotly Express

Should we raise a warning or an error in the following case (which is very contrived of course)
```
import plotly.express as px
df = px.data.tips()
fig = px.scatter(df, x='tip', y='total_bill', color='day', facet_col='sex',
                 labels={'tip':'sex', 'day':'sex'})
fig.show()
```
in this case, in the hover only the value corresponding to `x='tip'` appears.