Modifying build_arg_string function to replace blank space
characters with octal code 040, and added a doctest to
check various combinations with single and double quotes
included.

Supersedes workaround for subplot's autolabel (-A)
and title (-T) parameters in
a9d167d,
4126c16, and
eadb847.

Doesn't work yet, as the filename will contain the 040 octal
code, but committing to have the diff available for review.

Also added a regression test for
FORMAT_DATE_MAP="o dd".

So that fig.savefig won't insert `\040` characters when saving filenames with spaces. Resolves problem mentioned in https://github.com/GenericMappingTools/pygmt/pull/1487/files#r703116544

Instead of converting spaces to \040 in proj4 strings, just remove them directly. Added parametrized unit tests to basemap and grdproject to check that it works.

Adapted from https://stackoverflow.com/questions/10386344/how-to-get-a-file-in-windows-with-a-colon-in-the-filename/25477235#25477235.

Co-Authored-By: Dongdong Tian <[email protected]>

Co-Authored-By: Dongdong Tian <[email protected]>