Tracking issue for VS Code use cases

[Discookie]

Tracking issue for various VS Code-related use cases, that are needed for making the UX for the "Reports in current file" on the IDE side better. See Ericsson/CodecheckerVSCodePlugin#149.

• There should be a way to query the list of files that will be analyzed by a CodeChecker analyze command, even if it's only displayed at the start of its execution.
• CodeChecker should store the reason why the analysis of a specific file failed. (And then be able to query it per-file with CodeChecker parse.)
• CodeChecker should store historical failed analyses, either incrementally or on a per-file basis, and not just the last run's succeeded/failed files.
• CodeChecker should be able to return whether a file has been analyzed or not. The three distinct cases here are not in the compilation database, in the compilation database but not analyzed, in the compilation database and analyzed.
• If CodeChecker is killed or a timeout is reached, the fact that a timeout occured should be saved as if it was an error, similar to storing failure reasons.