Refactor RedundantSemicolonsCleanUp to jdt.core.manipulation

[jjohnstn]

• refactor and rename to RedundantSemicolonsCleanUpCore
• fixes #1494

What it does

See title.

How to test

Run jdt.ui cleanup tests.

Author checklist

• [x] I have thoroughly tested my changes
• [x] The change is following the coding conventions
• [x] I have signed the Eclipse Contributor Agreement (ECA)

[jjohnstn]

Test failures are due to compiler changes concerning sealed classes and not related to this change.