Previously, there could be identical template/listener function names
for a component's template, if it had multiple similarly structured
nested sub-templates or listeners.
This resulted in build errors:
`Identifier '<SOME_IDENTIFIER>' has already been declared`
This commit fixes this by ensuring that the template index is included
in the `contextName` passed to the `TemplateDefinitionBuilder`
responsible for processing nested sub-templates.
Similarly, the template or element index is included in the listener
names.
PR Close#27766
48555f95c6