Fixes#7387
* Fix VM argument passing by .sbtopts file and JAVA_TOOL_OPTIONS environmental variable, improve launcher script integration test setup
* Fix sbt process not exiting in launcher test for --sbt-version
* Fix JAVA_TOOL_OPTIONS in launcher for linux/mac
Fixes#6530
Ref #6101
Problem
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Although having sbt server up by default is beneficial to well-tested
platforms like macOS, on less tested setups various native and/or
native-adjacent techniques we use could end up causing instability.
Solution
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This adds `--no-server` as a quick way of telling sbt not to start up
the sbt server or create virtual terminal.