Handle string read receipt data (#10606)

* Handle string read receipt data

Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>

* Test that we handle string read receipt data

Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>

* Add changelog for #10606

Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>

* Add docs

Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>

* Ignore malformed RRs

Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>

* Only surround hidden = ...

Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>

* Remove unnecessary argument

Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>

* Update changelog.d/10606.bugfix

Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>