[foreign-abi] RFR: 8242028: Remove C string to/from Java string utilities from Foreign class

[Athijegannathan Sundararajan]

Removing C string to/from Java string conversion utilities from Foreign.

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

Commit messages:
 - removed trailing whitespace.
 - 8242028: Remove C string to/from Java string utilities from Foreign class

Changes: https://git.openjdk.java.net/panama-foreign/pull/85/files
 Webrev: https://webrevs.openjdk.java.net/panama-foreign/85/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8242028
  Stats: 297 lines in 12 files changed: 104 ins; 181 del; 12 mod
  Patch: https://git.openjdk.java.net/panama-foreign/pull/85.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-foreign pull/85/head:pull/85

PR: https://git.openjdk.java.net/panama-foreign/pull/85