Bisq comes with an embedded Tor binary (provided by a third party), but we don't use it in this package because it's build for a FHS-abiding Linux distro; Meaning, Tor won't execute because it tried to load libraries from standard locations.
To address this problem, the Nix package launches an ephemeral Tor instance for Bisq. The approach works, but it does mean having to manage the tor process, something which is already handled well by Bisq.
This change modifies the Bisq Jar archive such that it launches the Tor binary from Nixpkgs, allowing Bisq to manage Tor as it does on other Linux distros and operating systems.
In a nutshell, when Bisq is launched it extracts a copy of the tor binary from its Jar file and saves it in the Bisq data directory. It is then executed from there. Since Nix doesn't know that Bisq has a runtime dependency on Tor, this change modifies the launcher script to contain a reference to Tor, thus convincing Nix that Tor is a runtime dependency.
This commit includes two changes to the *.desktop file:
1. Adds the Bisq version number.
2. Fixes the categories.
Sometimes the Bisq network raises the minimum required Bisq version. Adding the version number so that it's displayed in the desktop environment's menu makes it easy for users to confirm whether they have the necessary version.
Originally, there were two main categories assigned, which violates the standard. This change removes one of the main categories and adds an auxillary category.