RFR: 8237: Add support for Jolokia over Kubernetes proxy [v2]

[Martin Skarsaune]

> JMC-8273 : Use the jolokia protocol over a kubernetes http proxy.
> 
> Testing connectivity:
> - [x]  Docker desktop kubernetes 
> - [x]  Azure AKS
> - [x]  Amazon EKS
> - [x]  Google GKE
> 
> Other things observed:
> 
> - [x] * Option to install agent should be disabled (debug difference with jolokia) - ***see below****
> - [x] * Warning: NLS missing message: JmcKubernetesPreferenceForm_LogErrorsTooltip in: org.openjdk.jmc.kubernetes.preferences.messages
> - [x] * SLF4J(W): No SLF4J providers were found. ***OK for now, can investigate more later***
> SLF4J(W): Defaulting to no-operation (NOP) logger implementation
> SLF4J(W): See https://www.slf4j.org/codes.html#noProviders for further details.
> - [x] Unlocking secrets now appear on startup. Should not be needed unless there are credentials used. (fixed)

Martin Skarsaune has updated the pull request incrementally with one additional commit since the last revision:

  JMC-8237: Remove unneeded changes

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

Changes:
  - all: https://git.openjdk.org/jmc/pull/576/files
  - new: https://git.openjdk.org/jmc/pull/576/files/ca1ee0a6..3cc408ef

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jmc&pr=576&range=01
 - incr: https://webrevs.openjdk.org/?repo=jmc&pr=576&range=00-01

  Stats: 37 lines in 6 files changed: 0 ins; 18 del; 19 mod
  Patch: https://git.openjdk.org/jmc/pull/576.diff
  Fetch: git fetch https://git.openjdk.org/jmc.git pull/576/head:pull/576

PR: https://git.openjdk.org/jmc/pull/576