Ensure DeleteUser is not allowed to Delete Orgs and visa versa

[6543]

as title (extend/come up in #10125)

[codecov-io]

Codecov Report

Merging #10134 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master   #10134      +/-   ##
==========================================
+ Coverage   43.39%    43.4%   +<.01%     
==========================================
  Files         576      576              
  Lines       79624    79628       +4     
==========================================
+ Hits        34553    34559       +6     
+ Misses      40792    40789       -3     
- Partials     4279     4280       +1

Impacted Files	Coverage Δ
models/user.go	49.37% <100%> (+0.12%)	⬆️
models/org.go	70.32% <100%> (-0.46%)	⬇️
modules/queue/unique_queue_disk_channel.go	54.48% <0%> (+1.92%)	⬆️
models/unit.go	39.5% <0%> (+2.46%)	⬆️

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[adelowo]

Will be nice to add a test for this though.

[adelowo]

Do we want to add the reverse? Make sure regular users cannot be deleted from DeleteOrganization

gitea/models/org.go

Lines 257 to 275 in b3c72a7

	// DeleteOrganization completely and permanently deletes everything of organization.
	func DeleteOrganization(org *User) (err error) {
	sess := x.NewSession()
	defer sess.Close()
	if err = sess.Begin(); err != nil {
	return err
	}
	if err = deleteOrg(sess, org); err != nil {
	if IsErrUserOwnRepos(err) {
	return err
	} else if err != nil {
	return fmt.Errorf("deleteOrg: %v", err)
	}
	}
	return sess.Commit()
	}

[guillep2k]

Will keep the check at routers/api/v1/admin/user.go:231 ?

[6543]

Will keep the check at routers/api/v1/admin/user.go:231 ?

@guillep2k
would say yes -> normal error is 500 and with check it returns 422 in this case ...

[6543]

@adelowo looks like DeleteOrg had already a check ..
I remove redundancy (deleteOrg is only used in DeleteOrganization) ...
@guillep2k I also moved tests to UnitTests

[6543]

ready to merge 🚀