[Feat] v.buffer should be able to read both major and minor axis and angle of major axis from data column

[isaacullah]

Describe the problem
v.buffer option 'column' allows buffer distance to be read from a numerical column in the input vector's table, but this can only allow for the buffer distance along the major axis. So, with points as input, this can only create circular buffers of varying sizes. If I have two relevant columns, such as width and length of a site, I cannot create an oval buffer. I cannot also control the angle of the major axis if I have a third column of azimuth per site.

Describe the solution you'd like
Option 'column' should be dropped, and input options 'distance,' 'minordistance,' and 'angle' should be updated to take numerical values OR column names. Alternatively, input option 'column' should take multiple input column names separated by commas in the order of "major distance column, minor distance column, axis column,' and should fill in with numerical values from the other fields if only one or two columns are entered.

Describe alternatives you've considered
As far as i have been able to tell, there is currently no way to read in major and minor buffer distances and axis from a database column.

Additional context
I discovered this while compiling instructions for operations in GRASS for a chapter that will be included in the second edition of the Geomorphometry book.

[sudhanshu112233shukla]

I think enhance v.buffer to support elliptical buffers by reading major axis, minor axis, and rotation angle from attribute columns. Modify v.buffer/main.c to fetch these values and implement elliptical buffering using GEOS or internal geometry functions.