Update the mobile phone data processing function, See [example](https://github.com/ni1o1/transbigdata/blob/main/docs/source/gallery/Example%206-Mobile%20phone%20data%20processing.ipynb) for detail usage. Add functions:
- `transbigdata.mobile_stay_move`: Input trajectory data and gridding parameters, identify stay and move.
- `transbigdata.mobile_stay_dutation`: Input the stay point data to identify the duration during night and day time.
- `transbigdata.mobile_identify_home`: Identify home location from mobile phone stay data. The rule is to identify the locations with longest duration in night time.
- `transbigdata.mobile_identify_work`: Identify work location from mobile phone stay data. The rule is to identify the locations with longest duration in day time on weekdays(Average duration should over `minhour`).
- `transbigdata.mobile_plot_activity`: Plot the activity plot of individual.