Add support for specifying additional JVM arguments

[ShadelessFox]

This pull request adds a new launcher argument, --launcher.additionalVmargs, that is supposed to be followed by a list of locations of files containing extra JVM arguments. Locations can potentially contain environment-variable strings in the form of %VariableName% regardless of the platform:

--launcher.additionalVmargs
%XDG_DATA_HOME%/DBeaverData/settings/dbeaver.vmargs
%HOME%/.local/share/DBeaverData/settings/dbeaver.vmargs

The launcher will attempt to read a file for every location in the declaration order until it succeeds. JVM arguments specified in such a file have higher priority than the ones defined in the launcher arguments or the configuration file.

A file containing extra JVM arguments follows the same structure as any other configuration file: every new argument is placed on its own line:

-Xms64M
-Xmx128M

The argument is intended to be used by developers of Eclipse RCP applications. It can be defined as <programArgs> in the .product file to allow end-users to specify JVM arguments if they can't do that otherwise by modifying the configuration file.

Additionally, 7e684f2 brings configuration file resolution for the console launcher with the -cli postfix in addition to the existing c postfix on Windows.

[github-actions]

Test Results

  660 files  ±0    660 suites  ±0   1h 16m 57s ⏱️ - 1m 7s
2 201 tests ±0  2 154 ✅ ±0   47 💤 ±0  0 ❌ ±0 
6 747 runs  ±0  6 604 ✅ ±0  143 💤 ±0  0 ❌ ±0 

Results for commit 6962fda. ± Comparison against base commit 2815608.