Parse flag thresholds and provide them as double values in BridgeNetworkStatus and RelayNetworkStatusVote
Sample data:
flag-thresholds stable-uptime=3768284 stable-mtbf=2721929 fast-speed=55000 guard-wfu=98.000% guard-tk=691200 guard-bw-inc-exits=364000 guard-bw-exc-exits=366000 enough-mtbf=1 ignoring-advertised-bws=0
flag-thresholds stable-uptime=1291379 stable-mtbf=460242 fast-speed=102000 guard-wfu=98.000% guard-tk=691200 guard-bw-inc-exits=4670000 guard-bw-exc-exits=3820000 enough-mtbf=1 ignoring-advertised-bws=1