…before setting source root to the package base

fix (masonry.builders.wheel): fix substitution in string formation
new (tests.masonry.builders.test_wheel): test to check if file is excluded in wheel, when listed in gitignore and src layout is used

…dIncludeFile` to store the original path to the project's root folder

new (masonry.builders.builder): method to return relative path to project's root for `BuildIncludeFile`
change (masonry.builders.builder): use relative path to project's root when checking if BuildIncludeFile is excluded
fix (masonry.builders.wheel): fix substitution in string formation

…ttribute of `Builder`

fix (masonry.builders.builder): fix some type hints