Review and move 'lowvoltage' scripts

[IlkaCu]

Scripts from DP-section 'lowvoltage' need to be reviewed, adjusted and moved to the new repo:

• [ ] ego_dp_lv_substation.sql
• [ ] ego_dp_lv_substation_voronoi.sql
• [ ] ego_dp_lv_loadcut.sql
• [ ] ego_dp_lv_griddistrict.sql
• [ ] ego_dp_lv_consumption_peakload.sql

[nesnoj]

Done