[FEATURE] Generate graphs using blif2graph

[mario33881]

Add an option to use blif2graph to generate graphs inside vscode.

Properties of this feature:

• it must be optional: if the user wants to use blif2graph, they can. The extension must work with and without blif2graph.
• it should check if the blif2graph executable is available in PATH and call it when the user clicks on something
• it should allow the user to manually type blif2graph binary's path in the configs when its executable is not in PATH
• it should be integrated in vscode as much as possible

  It would be nice if the user could right click and choose an option "Generate BLIF graph".

  A preview window could open and show blif2graph's output. (the user might have an option called "Generate BLIF graph and open preview")

  It would be even better if the extension could keep generating the graph every time the user saves changes. (when the user wants to... A checkbox in the configs?)