RFR: JDK-8241742 - Remove the preview status for methods introduced for Text Blocks

[Jim Laskey]

Please take the time to review the code changes to remove preview status for String::stripIndent, String::translateEscapes and String::formatted. The changes are pretty light-weight and shouldn't take too long to review. Mostly involves removing "preview" trappings.

Cheers,

-- Jim

webrev: http://cr.openjdk.java.net/~jlaskey/8241742/webrev-00 <http://cr.openjdk.java.net/~jlaskey/8241742/webrev-00>

JBS: https://bugs.openjdk.java.net/browse/JDK-8241742 <https://bugs.openjdk.java.net/browse/JDK-8241742>
CSR: https://bugs.openjdk.java.net/browse/JDK-8241747 <https://bugs.openjdk.java.net/browse/JDK-8241747>
JEP: https://bugs.openjdk.java.net/browse/JDK-8236934 <https://bugs.openjdk.java.net/browse/JDK-8236934>