ExplicitImports issues

ExplicitImports analysis:

However, module LinearMapsAA has stale explicit imports for this 1 unused
name:

• blockdiag is unused but it was imported from SparseArrays at
/Users/fessler/.julia/packages/LinearMapsAA/P0GrF/src/block_diag.jl:13:21

Additionally, module LinearMapsAA accesses 3 names from non-owner modules:

• hcat has owner Base but it was accessed from LinearMaps at
/Users/fessler/.julia/packages/LinearMapsAA/P0GrF/src/cat.jl:82:20
• mul! has owner LinearAlgebra but it was accessed from LinearMaps
at
/Users/fessler/.julia/packages/LinearMapsAA/P0GrF/src/multiply.jl:83:16
• vcat has owner Base but it was accessed from LinearMaps at
/Users/fessler/.julia/packages/LinearMapsAA/P0GrF/src/cat.jl:95:20

Additionally, module LinearMapsAA accesses 7 non-public names:

• AbstractRotation is not public in LinearAlgebra but it was
accessed via LinearAlgebra at
/Users/fessler/.julia/packages/LinearMapsAA/P0GrF/src/ambiguity.jl:26:54
• AdjointAbsVec is not public in LinearAlgebra but it was accessed
via LinearAlgebra at
/Users/fessler/.julia/packages/LinearMapsAA/P0GrF/src/ambiguity.jl:30:28
• BlockDiagonalMap is not public in LinearMaps but it was accessed
via LinearMaps at
/Users/fessler/.julia/packages/LinearMapsAA/P0GrF/src/block_diag.jl:31:20
• CompositeMap is not public in LinearMaps but it was accessed via
LinearMaps at
/Users/fessler/.julia/packages/LinearMapsAA/P0GrF/src/multiply.jl:81:62
• RealHermSymComplexHerm is not public in LinearAlgebra but it was
accessed via LinearAlgebra at
/Users/fessler/.julia/packages/LinearMapsAA/P0GrF/src/ambiguity.jl:10:62
• RealHermSymComplexSym is not public in LinearAlgebra but it was
accessed via LinearAlgebra at
/Users/fessler/.julia/packages/LinearMapsAA/P0GrF/src/ambiguity.jl:9:64
• TransposeAbsVec is not public in LinearAlgebra but it was accessed
via LinearAlgebra at
/Users/fessler/.julia/packages/LinearMapsAA/P0GrF/src/ambiguity.jl:31:28