Enable extract_data_apsimx Function to Support File Paths with Spaces

[Chloe0317]

This pull request modifies the extract_data_apsimx function to handle file and directory paths that contain spaces.

[Chloe0317]

@femiguez Hi Fernando,

I created this pull request which will allow spaces in the file links for your consideration as sometimes the paths are likely to contain white spaces, e.g., our uni's OneDrive system has spaces in the root folder name and in links to channel files that we don't have authorities to change.

Thanks.

[femiguez]

@Chloe0317 Originally in the package I did not allow path spaces because APSIM couldn't handle them. At some point this was fixed, but only for APSIM Next Gen. I allow spaces in paths for files by setting the 'apsimx_options(allow.path.spaces = TRUE)'. It is FALSE by default and I might set it to TRUE in the future. However, I want users to be aware of this, as it can cause problems. Please try the global option 'apsimx_options(allow.path.spaces = TRUE)' and let me know if it fixes your problem. Note that there cannot be spaces in the path to the APSIM program with the exception of 'Program Files' in Windows.