[2.3] CS And DocBlock Fixes
minor #13066 [2.3] CS And DocBlock Fixes (GrahamCampbell)

This PR was squashed before being merged into the 2.3 branch (closes #13066).

Discussion
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[2.3] CS And DocBlock Fixes

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | N/A
| License       | MIT
| Doc PR        | N/A

##### This pull request provides some cs and docblock fixes.

@fabpot The second commit of the two applies the docblock fixes you wanted, using https://github.com/FriendsOfPHP/PHP-CS-Fixer/pull/887. I made 3 or 4 minor manual changes because people had put bulleted lists in the "short description" which is not allowed, so we were ending up with colons followed by full stops. I've moved those lists to be part of a "long description".

// cc @keradus

Commits
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83c15db [2.3] CS And DocBlock Fixes