Add `name` field for Blocks

Fixes #18420

CHANGELOG.md

@@ -11,6 +11,7 @@ Ansible Changes By Release
   the release.
 * removed 'package' from default squash actions as not all package managers support it and it creates errors when using loops,
   any user can add back via config options if they don't use those package managers or othewise avoid the errors.
+* Blocks can now have a `name` field, to aid in playbook readability.
 
 ###Deprecations:
 * Specifying --tags (or --skip-tags) multiple times on the command line

lib/ansible/playbook/block.py

@@ -30,12 +30,16 @@ from ansible.playbook.taggable import Taggable
 
 class Block(Base, Become, Conditional, Taggable):
 
+    # main block fields containing the task lists
     _block            = FieldAttribute(isa='list', default=[], inherit=False)
     _rescue           = FieldAttribute(isa='list', default=[], inherit=False)
     _always           = FieldAttribute(isa='list', default=[], inherit=False)
+
+    # other fields
+    _any_errors_fatal = FieldAttribute(isa='bool')
     _delegate_to      = FieldAttribute(isa='list')
     _delegate_facts   = FieldAttribute(isa='bool', default=False)
-    _any_errors_fatal = FieldAttribute(isa='bool')
+    _name             = FieldAttribute(isa='string', default='')
 
     # for future consideration? this would be functionally
     # similar to the 'else' clause for exceptions