Make limit configurable for constrained table in loose foreign key yml file

The following discussion from !189738 (merged) should be addressed:

• @OmarQunsulGitlab started a discussion: (+4 comments)

  @tianwenchen out of curiosity, why do we need a LFK between two tables on the same database? is this temporary?

  I came across this because of this slack thread (internal link)

  CC: @l.rosa

  @tianwenchen @OmarQunsulGitlab can we make the DELETE_LIMIT configurable?