[clang] [clang][analyzer] Remove boolean per-entry-point metrics (PR #162817)

[Arseniy Zaostrovnykh via cfe-commits]

necto wrote:

This is the first step out of three I plan instead of #162089 . The end goal is to record both PathRunningTime and SyntaxRunningTime per entry point.
- in this step, I remove boolean statistics as I don't find them carrying their weight in terms of complexity.
- in the next step, I will propose more accurate representation of the unsigned statistics that were never set for a particular entry point in the CSV - as empty cells, rather than 0
- in the final step, I will add the SyntaxRunningTime in addition to the existing PathRanningTime statistic, which will be only set for entry points that underwent syntax analysis

https://github.com/llvm/llvm-project/pull/162817