RFR: 8537: Minor discrepancies between Oracle JMC and Open JMC

[Suchita Chaturvedi]

This PR is addressing the Minor discrepancies between Oracle JMC and Open JMC. 

- Few accessibility related changes.
- Some JDK and eclipse version changes in help pages. 
- Few links are updated from http to https.
- Copyright year changes.
- Owasp Encoder was updated to 1.2.3 but license was still mentioning 1.2.2 updated that as well.

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

Commit messages:
 - 8537: Minor discrepancies between Oracle JMC and Open JMC

Changes: https://git.openjdk.org/jmc/pull/709/files
  Webrev: https://webrevs.openjdk.org/?repo=jmc&pr=709&range=00
  Issue: https://bugs.openjdk.org/browse/JMC-8537
  Stats: 212 lines in 19 files changed: 152 ins; 0 del; 60 mod
  Patch: https://git.openjdk.org/jmc/pull/709.diff
  Fetch: git fetch https://git.openjdk.org/jmc.git pull/709/head:pull/709

PR: https://git.openjdk.org/jmc/pull/709