Component-scope twin of provideFormField. Returns plain Provider[]
for a component's providers / viewProviders, so a sub-tree can carry its
own form-field defaults without an environment injector.
The case this exists for is withFieldSkin: a table region that wants every
filter control bare, or a dialog that wants fill, while the rest of the
app keeps the root default.
Nearest-wins and replace, not merge - same semantics as the environment
tier. A component-level call shadows the app-wide config for that sub-tree
rather than deep-merging into it, so re-state any feature the sub-tree still
needs.