Open the homonymic tree nodes for dialog editor entrypoint selection

[skateman]

The dialog editor has an option to set a field dynamic, if this is enable there's an entry point selection tree available under the Options tab. If you're editing an already existing field with an entry point selected, the tree nodes to the entry point aren't expanded.

However, the entry point doesn't include a domain prefix, it is possible that the same entry point is available under a different domain. We discussed this with the automate folks and the only solution is to expand all the homonymic nodes under all possible automate domain prefixes.

I added an optional block evaluation to the TreeController#fetch_tree method that runs before the tree is being build. By passing a block to this method, we can easily define different behavior for certain trees without defining extra arguments for the method. We might want to redesign this block evaluation in the future to run directly in the TreeBuilder but for now it is good as it is.

Depends on: ManageIQ/manageiq#18722

@miq-bot add_reviewer @martinpovolny
@miq-bot add_reviewer @himdel
@miq-bot add_reviewer @romanblanco
@miq-bot add_label pending core, changelog/yes, angular dialogs, automation/automate, trees

[miq-bot]

Checked commits skateman/manageiq-ui-classic@71d635f~...ff35fe1 with ruby 2.3.3, rubocop 0.52.1, haml-lint 0.20.0, and yamllint 1.10.0
3 files checked, 0 offenses detected
Everything looks fine. ⭐

[romanblanco]

Tested, works.
LGTM 👍

[skateman]

@miq-bot rm_label pending core

[skateman]

@miq-bot assign @mzazrivec