Add rule for space after cast and space after Not

[antonioeatgoat]

Please check if the PR fulfills these requirements

• The commit message follows our guidelines
• Tests for the changes have been added (for bug fixes/features)
• Docs have been added/updated (for bug fixes/features)

What kind of change does this PR introduce?
New feature.

What is the current behavior?
There are no checks on spaces after cast or spaces after Not operator. All the following lines pass the test:

• (string) $variable
• (string)$variable
• $variable = !$variable
• $variable = ! $variable
• if (!$variable)
• if (! $variable)

What is the new behavior?
The space after cast and Not operator is mandatory. These are the only accepted cases:

• (string) $variable
• $variable = ! $variable
• if (! $variable)

Does this PR introduce a breaking change?
No

Other information:
Both of the changes are addressable by phpcbf script.

[gmazzap]

@antonioeatgoat Thank you for the PR.
Can we split the space after the cast from the space after the "not" operator?

[antonioeatgoat]

@gmazzap done 👍