copy() debug output

[memsharded]

Changelog: Feature: Add verbose debug information (with -vvv) for conan.tools.files.copy() calls.
Docs: Omit

Close #4690

[iaavo]

The line os.makedirs(os.path.dirname(abs_dst_name), exist_ok=True) is throwing an exception in my case now.

Example to reproduce:

from conan import ConanFile
from conan.tools.files import copy

class BasicConanfile(ConanFile):
    name    = "test"
    version = "1.2.3"

    def generate(self):
        copy(self, "index.rst", "../library_a/source", ".")

Throws the exception:

ERROR: conanfile.py (test/1.2.3): Error in generate() method, line 11
        copy(self, "index.rst", "../library_a/source", ".")
        FileNotFoundError: [WinError 3] The system cannot find the path specified: ''

[memsharded]

The copy() function is mostly expecting absolute paths, I'd suggest to check that

However, I'll also revert this, as there is some risk of breaking for little benefit