RFR: 8263754: HexFormat 'fromHex' methods should be static

[Roger Riggs]

A number of HexFormat methods converting from strings to numbers do not use delimiter, prefix, suffix, and uppercase parameters and would be more convenient if the methods were static.

These  APIs were added early in JDK 17 and are being updated before GA.
This PR updates existing uses in the JDK but there may be compiler warnings in non-JDK source files.

   public boolean isHexDigit(int);
   public int fromHexDigit(int);
   public int fromHexDigits(java.lang.CharSequence);
   public int fromHexDigits(java.lang.CharSequence, int, int);
   public long fromHexDigitsToLong(java.lang.CharSequence);
   public long fromHexDigitsToLong(java.lang.CharSequence, int, int);

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Commit messages:
 - 8263754: HexFormat 'fromHex' methods should be static

Changes: https://git.openjdk.java.net/jdk/pull/3205/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3205&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8263754
  Stats: 47 lines in 5 files changed: 0 ins; 8 del; 39 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3205.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3205/head:pull/3205

PR: https://git.openjdk.java.net/jdk/pull/3205