[TESTBUG] Improve CDS test utils

Planning the following improvements to make CDS tests more robust, improve code reuse, ease of development and maintenance:

- create/use CDS utility methods for common patterns in CDS related tests:
     - creating an testlist
     - creating an archive, checking result
     - executing JVM with the archive
     - checking results and common error patterns

- use -Xshare:on when executing CDS tests, and use test utilities
   to filter out failures due to inability to map shared archive.
   This is a more deterministic way to execute CDS tests, rather than
   running tests with -Xshare:auto, which follows different code path
   and may hide issues.

- additional improvements came up as part of this work,
   such as jdk.test.lib.Utils:getTestName()