This introduces a new `state` column in `software` table.

Because node already has support for reporting various states of software
lifetime, this implementation stores the actual state of the software
installation.
What's not clear is that maybe it should store the requested state and the current state.

```plantuml
@startuml
start
repeat
  -> client request software in state available \n ""supplySupply?state="available""";
  if (already available ?) then (yes)
    :available;
  else (no )
    :install_requested;
    -> node starts building \n ""buildingSoftwareRelease"";
    :building;
    if ( build result? ) then ( node report build successful \n ""availableSoftwareRelease"" )
      :available;
    else (node report build error \n ""softwareReleaseError"" )
      :error;
    endif
  endif
repeat while ()

-> client request software in state destroyed \n ""supplySupply?state="destroyed""";;
:destroyed;
-> node notify software is deleted \n""destroyedSoftwareRelease"";
stop
@enduml
```