Add lfcoords tool

[casadoj]

This branch adds a new tool called lfcoords based on the paper by Burek and Smilovic (2023). This tool finds the appropriate coordinates in the LISFLOOD river network of any point, provided that the catchment area is known.

First, it uses the original coordinates and catchment area to find the most accurate pixel in a high-resolution map. Burek and Smilovic (2023) use MERIT (Yamazaki et al., 2019), which has a spatial resolution of 3 arc-seconds. The result of this first step is, for every point, a new value of coordinates and area, and shapefiles of the catchment polygons and the points in the high-resolution grid.

Second, it finds the pixel in the low-resolution grid (LISFLOOD static maps) that better matches the catchment shape derived in the previous step. As a result, for each point we obtained a new value of coordinates and area, and new shapefiles of the catchment polygons and points in the low-resolution grid.

I've added a test. The documentation is in the Wiki pages.