Fix some missing includes.

[hzeller]

And sort the headers in the affected files according to style guide.

Breakdown

util/RiseFallMinMax.cc:                  #include "MinMax.hh" for sta::MinMaxAll
sdc/Variables.cc:                        #include "PocvMode.hh" for sta::PocvMode
sdc/PortExtCap.cc:                       #include "NetworkClass.hh" for sta::Port
util/ReportTcl.cc:                       #include "Report.hh" for sta::Report
util/RiseFallMinMaxDelay.cc:             #include "StaState.hh" for sta::StaState
util/RiseFallMinMax.cc:                  #include "Transition.hh" for sta::RiseFallBoth
util/RiseFallValues.cc:                  #include "Transition.hh" for sta::RiseFallBoth
sdc/PortExtCap.cc:                       #include "MinMax.hh" for sta::MinMax
util/RiseFallMinMaxDelay.cc:             #include "MinMax.hh" for sta::MinMax
dcalc/DelayNormal.cc:                    #include "Delay.hh" for sta::Delay
dcalc/DelayScalar.cc:                    #include "Delay.hh" for sta::Delay
dcalc/DelaySkewNormal.cc:                #include "Delay.hh" for sta::Delay
util/RiseFallMinMaxDelay.cc:             #include "Delay.hh" for sta::Delay
dcalc/Delay.cc:                          #include "MinMax.hh" for sta::EarlyLate
dcalc/DelayNormal.cc:                    #include "MinMax.hh" for sta::EarlyLate
dcalc/DelayScalar.cc:                    #include "MinMax.hh" for sta::EarlyLate
dcalc/DelaySkewNormal.cc:                #include "MinMax.hh" for sta::EarlyLate
sdc/PortExtCap.cc:                       #include "Transition.hh" for sta::RiseFall
util/RiseFallMinMaxDelay.cc:             #include "Transition.hh" for sta::RiseFall
util/MinMax.cc:                          #include <array> for std::array
util/Transition.cc:                      #include <array> for std::array
power/VcdParse.cc:                       #include <stdexcept> for std::invalid_argument
dcalc/FindRoot.cc:                       #include <utility> for std::pair
util/StringUtil.cc:                      #include <utility> for std::pair
dcalc/Delay.cc:                          #include <string> for std::string
dcalc/DelayNormal.cc:                    #include <string> for std::string
dcalc/DelayScalar.cc:                    #include <string> for std::string
dcalc/DelaySkewNormal.cc:                #include <string> for std::string
liberty/Units.cc:                        #include <string> for std::string
network/VerilogNamespace.cc:             #include <string> for std::string
power/VcdParse.cc:                       #include <string> for std::string
search/PocvMode.cc:                      #include <string> for std::string
util/Error.cc:                           #include <string> for std::string
util/PatternMatch.cc:                    #include <string> for std::string
util/Report.cc:                          #include <string> for std::string
util/StringUtil.cc:                      #include <string> for std::string
util/Transition.cc:                      #include <string> for std::string
dcalc/ArnoldiDelayCalc.cc:               #include "Error.hh" for criticalError
search/GatedClk.cc:                      #include "Error.hh" for criticalError
search/Levelize.cc:                      #include "Error.hh" for criticalError
util/Report.cc:                          #include <cstdio> for printf
util/MachineWin32.cc:                    #include <cstdarg> for va_list

[hzeller]

I have scripts to fix more of these, but I'd need the clang-format to help sorting the headers afterwards. However, right now, clang-format would create a huge churn, so I leave this to after that has been run before.

[parallaxsw]

The reason the commit was called round1 is because I am in the process of doing this.
This PR does not help, it only creates conflicts.

[hzeller]

Sorry, I was mostly excited to see the addition of a .clang-tidy file and tried out if my scripts to fix some misc-include-cleaner work.

[parallaxsw]

You can pretty much bet on the fact that I will reject any PR that changes more than a few files without some sort of planning before it appears.