Better handling absence of build system

[tyuldashev]

Description Currently it's difficult to understand why bot fails if UTBot cannot generate test because neither make not CMake is presented in the project.

Use Case Assume user wants to try UTBot for test generation, so:

• She install UTBot server and plugin as described in manuals
• Opens empty project folder in the VStudio, immediately UTBot Wizard starts
• She setups everything in the wizard - everything looks fine
• Setups SFTP
• Adds some simple CPP file with code
• Tries to generate tests for it and accept all configuration suggestions from the bot

As result following error occur: It would we difficult to understand what happens and how to fix it

Suggested solutions

• In wizard detect (if possible) that build system is presented and show warning if it not
• At moment of test generation - show more specific error, explaining that either make or CMake should be presented.