[clang-format] SpacesInSquareBrackets should affect lambdas with parameters too

Summary:
This patch makes the `SpacesInSquareBrackets` setting also apply to C++ lambdas with parameters.

Looking through the revision history, it appears support for only array brackets was added, and lambda brackets were ignored. Therefore, I am inclined to think it was simply an omission, rather than a deliberate choice.

See https://bugs.llvm.org/show_bug.cgi?id=17887 and https://reviews.llvm.org/D4944.

Reviewers: MyDeveloperDay, reuk, owenpan

Reviewed By: MyDeveloperDay

Subscribers: cfe-commits

Patch by: mitchell-stellar

Tags: #clang-format, #clang

Differential Revision: https://reviews.llvm.org/D68473

llvm-svn: 373821