Add jls serialization to materials library.

[github-actions]

LineCableModels.jl/src/importexport/materialslibrary.jl

Lines 17 to 18 in 2502c78

	# TODO: Add jls serialization to materials library.
	# Issue URL: https://github.com/Electa-Git/LineCableModels.jl/issues/3

- The absolute path of the saved file, or `nothing` on failure.
"""
function save(
	library::MaterialsLibrary;
	file_name::String = "materials_library.json",
)::Union{String, Nothing}
	# TODO: Add jls serialization to materials library.
	# Issue URL: https://github.com/Electa-Git/LineCableModels.jl/issues/3
	file_name = isabspath(file_name) ? file_name : joinpath(@__DIR__, file_name)


	_, ext = splitext(file_name)
	ext = lowercase(ext)
	if ext != ".json"
		@warn "MaterialsLibrary only supports .json saving. Forcing extension for file '$file_name'."
		file_name = first(splitext(file_name)) * ".json"
	end

	try

		return _save_materialslibrary_json(library, file_name)

	catch e
		@error "Error saving MaterialsLibrary to '$(display_path(file_name))': $e"
		showerror(stderr, e, catch_backtrace())
		println(stderr)
		return nothing
	end
end

"""