[C++] Add QualifierAlignment to clang-format options

[pitrou]

Describe the enhancement requested

The QualifierAlignment clang-format option could help making our code style more uniform.

We generally use the const T idiom rather than T const, so we should specify the value Left to minimize code churn.

Component(s)

C++, Developer Tools

[pitrou]

This was originally suggested by @AntoinePrv .

[pitrou]

Issue resolved by pull request 47501
#47501