MINOR: clean up Streams assignment classes and tests

[ableegoldman]

First set of cleanup pushed to followup PR after KIP-441 Pt. 5. Main changes are:

1. Moved RankedClient and the static buildClientRankingsByTask to a new file
2. Moved Movement and the static getMovements to a new file (also renamed to TaskMovement)
3. Consolidated the many common variables throughout the assignment tests to the new AssignmentTestUtils
4. New utility to generate comparable/predictable UUIDs for tests, and removed the generic from TaskAssignor and all related classes

Keep in mind, this does not represent the sum whole of all cleanup we'd like to do. But if there's anything you had in mind that you feel would fit in with the other changes in this PR, feel free to point it out

[vvcephei]

test this please

[vvcephei]

Thanks for the cleanup!

[vvcephei]

Is this just important to produce stable test results for verification?

[vvcephei]

Failed due to github outage.

Retest this, please

[vvcephei]

Hey @ableegoldman , looks like there are some problems:

java.lang.Exception: No public static parameters method on class org.apache.kafka.streams.processor.internals.StreamsPartitionAssignorTest


java.lang.ClassCastException: class java.util.UUID cannot be cast to class java.lang.Integer (java.util.UUID and java.lang.Integer are in module java.base of loader 'bootstrap')
	at java.base/java.lang.Integer.compareTo(Integer.java:59)
	at java.base/java.util.TreeMap.getEntry(TreeMap.java:350)
	at java.base/java.util.TreeMap.get(TreeMap.java:277)
	at org.apache.kafka.streams.processor.internals.assignment.StickyTaskAssignorTest.shouldNotHaveSameAssignmentOnAnyTwoHosts(StickyTaskAssignorTest.java:418)

[vvcephei]

test this please

[vvcephei]

test this please