Use ndsize_t for function dimension related arguments

[gicmo]

Follow up to issue #473, and related to G-Node/nix-mx#114

• [x] SampledDimension::axis(const size_t count, const size_t startIndex = 0)
• [x] RangeDimension::axis(const size_t count, const size_t startIndex = 0)
• [x] SampledDimension::positionAt(const size_t index) const
• [x] SampledDimension::operator[](const size_t index)
• [x] RangeDimension::operator[](const size_t index)
• [x] RangeDimension::tickAt(const size_t index) const

[gicmo]

PR #629 a few checks that are not really necessary. I.e. src/Dimensions.cpp line 192. We really only need to make that check if we need a size_t, e.g. for creating a std::vector or accessing elements in a vector. We should also create tests for arrays that are bigger then 32 bits in size to check if the code actually works. ;)

[jgrewe]

closed via #632