When you permanently destroy a specific project from the command line, the following
additional good things now happen:

• the direct orhpan milestones are removed too (instead of leaving them orphan, broken, invisible forever)
• all children projects emerge like cute bubbles by one level (instead of having them orphan, broken, invisible forever)
• the parent project is eventually restored as "without sub-projects" (instead of having a broken root-project with bugged memberships)

This change has nothing to do with archived projects.

This change will only affect future usages of the destroy workflow, that is:

./bin/remove destroy PHID-OF-YOUR-PROJECT-TO-BE-DESTROYED

Example initial situation:

Project A
 [projectDepth: 0]
 [hasSubprojects: 1]
 [members: *automatic*, foo, bar]
 > Project B
  [projectDepth: 1]
  [hasSubprojects: 1]
  [members: *automatic*, foo, bar]
  > Project C
   [hasSubprojects: 0]
   [projectDepth: 2]
   [members: foo, bar]
   > Milestone C.1
    [projectDepth: 3]

Situation after destroying only project A:

Project B
 [projectDepth: 0]
 [hasSubprojects: 1]
 [members: *automatic*, foo, bar]
 > Project C
  [projectDepth: 1]
  [hasSubprojects: 0]
  [members: foo, bar]
  > Milestone C.1
   [projectDepth: 2]

Situation after destroying only project B:

Project A
 [projectDepth: 0]
 [hasSubprojects: 1]
 [members: *automatic*, foo, bar]
 > Project C
  [projectDepth: 1]
  [hasSubprojects: 0]
  [members: foo, bar]
  > Milestone C.1
   [projectDepth: 2]

Situation after destroying only project C:

Project A
 [projectDepth: 0]
 [hasSubprojects: 1]
 [members: *automatic*, foo, bar]
 > Project B
  [projectDepth: 1]
  [hasSubprojects: 0]
  [members: foo, bar]

Situation after destroying only milestone C.1:

Project A
 [projectDepth: 0]
 [hasSubprojects: 1]
 [members: *automatic*, foo, bar]
 > Project B
  [projectDepth: 1]
  [hasSubprojects: 1]
  [members: *automatic*, foo, bar]
  > Project C
   [hasSubprojects: 0]
   [projectDepth: 2]
   [members: foo, bar]

Run multiple times the destroy workflow under every imaginable case,
to violently destroy a projects tree, leaf by leaf. We suggest to run it
with the trace option. Example:

./bin/remove destroy --trace PHID-PROJ-s0met1ng

To run the above workflow multiple times, you may appreciate a dump:

./bin/storage dump | gzip > dump.sql.gz

So you can easily restore it whenever you want:

zcat dump.sql.gz | ./bin/storage shell

• Delete simple milestone
  • create a new simple project "A" with milestone "M" and delete "M"
  • deletion still works on milestone "M"
• Delete simple project
  • create a new simple project "A" with a workboard and destroy "A":
  • deletion still works on project "A"
  • workboard is still not accessible
  • if there were tasks, they are still there but without tag "A"
• Delete project with milestone (T15913)
  • create a new project "A" with a milestone "B" and delete "A"
  • deletion still works on project "A"
  • milestone "B" is finally nuked from the database and you do not see it anymore in the phabricator_project table
• Delete a project with sub-projects (T15918)
  • create a new project "A" with a sub-project called "B" and delete "A"
  • deletion still works on project "A"
  • project "B" becomes a root-project and it has depth "0" again and it's usable, instead of having it borked with "You Shall Not Pass"
• Delete a sub-project (T15697)
  • create a new project "A" with a sub-project called "B" and delete "B"
  • deletion still works on project "B"
  • project "A" is usable again like "B" never existed, so you can change memberships and all the things, instead of having it borked

Closes T15697
Closes T15913
Closes T15918