symmTensor: Add support for the innerSqr function

applications/test/tensor/Test-tensor.C

...sionedTypes/dimensionedSymmTensor/dimensionedSymmTensor.C

...sionedTypes/dimensionedSymmTensor/dimensionedSymmTensor.H

...s/DimensionedSymmTensorField/DimensionedSymmTensorField.C

...s/DimensionedSymmTensorField/DimensionedSymmTensorField.H

...s/FieldFields/symmTensorFieldField/symmTensorFieldField.C

...s/FieldFields/symmTensorFieldField/symmTensorFieldField.H

src/OpenFOAM/fields/Fields/symmTensorField/symmTensorField.C

src/OpenFOAM/fields/Fields/symmTensorField/symmTensorField.H

...ields/GeometricSymmTensorField/GeometricSymmTensorField.C

...ields/GeometricSymmTensorField/GeometricSymmTensorField.H

src/OpenFOAM/primitives/SymmTensor/SymmTensorI.H

src/OpenFOAM/primitives/SymmTensor2D/SymmTensor2DI.H