This commit adds new a type `Neighbor::AddressMactehr` which is used
to filter and find a neighbor (child/router) with a given MAC address
matching a given `Neighbor::StateFilter`. This new type helps simplify
related code in `ChildTable`/`RouterTbale`.
This commit updates `ChildTable` class. It mainly adds support for
using range-based `for` loops to iterate over all child entries
(matching a given state filter). It also simplifies the `Iterator`
implementation (removing the now unused behavior to start the
iteration from a specific child in the table). The unit test
`test_child_table` is also updated to add tests for the newly added
behavior.
This commit introduces a new class `ChildTable` as part of OpenThread
core. This class provides methods for iterating through the child
table and searching for a specific child (based on short/extended
address and/or child state). This commit also adds a unit test for the
newly added `ChildTable class.
Abtin Keshavarzian