RFR: 6627: Bring bundles to core

[Alex Macdonald]

This PR addresses JMC-6627 [[0]](https://bugs.openjdk.org/browse/JMC-6627) in which it would be nice to bring some bundles from application to core. Most notably, **flightrecorder.configuration** which has a PR open for review [[1]](https://github.com/openjdk/jmc/pull/469) and is also tracked by JMC-7307 [[2]](https://bugs.openjdk.org/browse/JMC-7307), and **RJMX** which is also tracked by JMC-7069 [[3]](https://bugs.openjdk.org/browse/JMC-7069).

While #469 is still under review, I copied a branch of it and squashed all the commits down into one commit [[4]](https://github.com/openjdk/jmc/commit/72c08b3f65671d16fcbb1333a5782e10ac9c874f) for easier rebasing. Review comments for flightrecorder.configuration should go towards #469.  RJMX does have reliance on the flightrecorder.configuration changes (and some still in ui.common), so the second commit [[5]](https://github.com/openjdk/jmc/commit/f1c828dd46f24d9075cd3eedbf5a15bb9daf9a72) here is where this PR really starts. Once #469 is merged I can rebase this PR so that it handles RJMX.

As mentioned in JMC-6627 [[0]](https://bugs.openjdk.org/browse/JMC-6627), because of the way Eclipse is intertwined with the RJMX code, this isn't a straightforward movement of classes. There are some parts that will need to stay on the side of jmc/application, but much of the code can come over to jmc/core with modification. This is accomplished by having a `rjmx.common` module in core, and keeping regular `rjmx` in application.

There are a handful of classes (e.g., `NameConverter`, `SyntheticAttributeRepository`, `SyntheticNotificationRepository`, ..) that use Eclipse to initialize them by parsing through values in plugin.xml, or use classes (like Persistence and Preferences) that are closely tied to the Eclipse RCP side of things. I brought over these classes to core and kept the code that initializes the values from extensions on the application side, so they could be set from application -> core when running JMC, but for third-party applications that want to use the RJMX code then they might not need/require this initialization.

I still have to go back and cleanup some of the license headers, but wanted to get this PR on the radar.

[0] https://bugs.openjdk.org/browse/JMC-6627
[1] https://github.com/openjdk/jmc/pull/469
[2] https://bugs.openjdk.org/browse/JMC-7307
[3] https://bugs.openjdk.org/browse/JMC-7069
[4] https://github.com/openjdk/jmc/commit/72c08b3f65671d16fcbb1333a5782e10ac9c874f
[5] https://github.com/openjdk/jmc/commit/f1c828dd46f24d9075cd3eedbf5a15bb9daf9a72

-------------

Commit messages:
 - Update license headers
 - Restore rjmx.services.jfr Messages.java
 - 6627: Bring bundles to core
 - 7307: Move org.openjdk.jmc.flightrecorder.configuration bundle from application to core

Changes: https://git.openjdk.org/jmc/pull/531/files
 Webrev: https://webrevs.openjdk.org/?repo=jmc&pr=531&range=00
  Issue: https://bugs.openjdk.org/browse/JMC-6627
  Stats: 14583 lines in 556 files changed: 6793 ins; 6548 del; 1242 mod
  Patch: https://git.openjdk.org/jmc/pull/531.diff
  Fetch: git fetch https://git.openjdk.org/jmc.git pull/531/head:pull/531

PR: https://git.openjdk.org/jmc/pull/531