Extract AbstractResumedStatement
Separate out data structures related to statement source traversal
into a dedicated class.
This lowers the footprint required to implement StatementContextBase,
as well as lowering clutter around which functionality is related
to which part.
JIRA: YANGTOOLS-652
Change-Id: I811c6fcf3bfba83421609af13dfed8fe445184b9
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>
(cherry picked from commit
d3425a5bdd83c76d186d59f711d3c41cd24c1fee)
(cherry picked from commit
735f3c1d9c2243eac0976e0db7af9d62a4e88f98)