Add swift-format

[pdil]

• Added swift-format configuration and applied to entire project.

Adding the following commit hook in .git/hooks/pre-commit is recommended:

# swift format changed files
git diff --diff-filter=d --staged --name-only | grep -e '\(.*\).swift$' | while read line; do
    swift format -irp "${line}";
    git add "$line";
done