Add (recover) quotes around link flags

[jgsogo]

Changelog: Bugfix: Recover quotes around linker flags in CMake generators, fix failure with Macos frameworks
Docs: omit

In PR #6780 we lost the quotes we were adding around frameworks, without them CMake generated files are not valid, and the link step fails (#7321).

Note.- This is reintroduced for backward compatibility, but the proper way to declare the frameworks is to add them to the cpp_info.frameworks dedicated list:

                def package_info(self):
                    if not self.options.use_components:
                        # self.cpp_info.exelinkflags.extend(['-framework Foundation'])
                        self.cpp_info.frameworks.extend(['Foundation'])
                    else:
                        # self.cpp_info.components["cmp"].exelinkflags.extend(['-framework Foundation'])
                        self.cpp_info.components["cmp"].frameworks.extend(['Foundation'])

Fix #7321
Close #1251