Task tree structure will be messed up with repeated task "terminal" names

[dcecile]

Result looks similar to #79, but this is caused by repeated "terminal" names. I have a root build and also nested build:

version: '3'
tasks:
  build:
    cmd: echo build
  other:build:
    cmd: echo other build

All of the nested repeats get duplicated into the root of the task tree view.

(Currently running v0.3.1)

[yoiang]

We have this with out project as well, the root tasks are a big mess with numerous duplicates that make it unclear which it which