RFR: 8289255: update Eclipse .classpath and other configuration files

[Andy Goryachev]

On Mon, 27 Jun 2022 23:19:36 GMT, Andy Goryachev <duke at openjdk.org> wrote:

> summary of changes:
> - fixed .classpath files
> - set UTF-8 encoding in the eclipse project config files

Please review.  This PR is blocking the rest of fixes in [JDK-8289379](https://bugs.openjdk.org/browse/JDK-8289379)

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PR: https://git.openjdk.org/jfx/pull/804