RFR: JDK-8290011: IGV: Remove dead code and cleanup [v14]

[Tobias Holenstein]

> Remove dead code from the IGV code base. There are many unused or redundant functions in the code

Tobias Holenstein has updated the pull request incrementally with one additional commit since the last revision:

  merge current master

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/10197/files
  - new: https://git.openjdk.org/jdk/pull/10197/files/c213bed5..b714dfd4

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10197&range=13
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10197&range=12-13

  Stats: 512 lines in 45 files changed: 88 ins; 144 del; 280 mod
  Patch: https://git.openjdk.org/jdk/pull/10197.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10197/head:pull/10197

PR: https://git.openjdk.org/jdk/pull/10197