[split] Move gvm plugin to oh-my-fish/plugin-gvm

https://github.com/oh-my-fish/plugin-gvm

plugins/gvm/gvm.fish

-function gvm
-  bash -c '. ~/.gvm/bin/gvm-init.sh; gvm "$@"' gvm $argv
-end

plugins/gvm/gvm.load

-for gvm_path in (find $HOME/.gvm/*/current/bin -maxdepth 0)
-  _prepend_path $gvm_path
-  set -l module_info (echo $gvm_path | perl -ne 'm|(.*/.gvm/(\w+)/current)/bin| && print "$1 $2"')
-  set -l module_dir (echo $module_info | awk -F' ' '{print $1}')
-  set -l module_name (echo $module_info | awk -F' ' '{print $2}')
-  set -l module_home (echo $module_name | tr '[:lower:]' '[:upper:]')_HOME
-  set -gx "$module_home" $module_dir
-end
-
-# ONLY checked on OSX! Please add for other OS's...
-if test -z $JAVA_HOME
-  if test -f "/usr/libexec/java_home"
-    set -gx JAVA_HOME (/usr/libexec/java_home)
-  end
-
-  if test -z $JAVA_HOME
-    set -l java_homes "/Library/Java/Home" "/System/Library/Frameworks/JavaVM.framework/Home"
-    for file in $java_homes
-      if test -d $file
-        set -gx JAVA_HOME $file
-        break
-      end
-    end
-  end
-end
-
-if test -z $JAVA_HOME
-  echo "GVM: JAVA_HOME not set please set JAVA_HOME."
-end
-