- previously introduced `getOrDefault` as a dictionary _get_ method,
now complete the transition and use it everywhere instead of
`lookupOrDefault`. This avoids mixed usage of the two methods that
are identical in behaviour, makes for shorter names, and promotes
the distinction between "lookup" access (ie, return a token stream,
locate and return an entry) and "get" access (ie, the above with
conversion to concrete types such as scalar, label etc).
- rationalized code dealing with extraction of name or indices from
coordinateSystems, polyBoundaryMesh, faBoundaryMesh, fvBoundaryMesh,
ZoneMesh to use internal implementations that allow direct
searching/matching without building an intermediate list of names.
- simpler and more efficient handling of patch group matching.
- avoids compiler ambiguity when virtual methods such as
IOdictionary::read() exist.
- the method was introduced in 1806, and was thus not yet widely used
