* [Java] Grow ArrayReadWriteBuf enough to match requested capacity.
Also handle requested capacity overflowing.
* [Java] Improve readability of ArrayReadWriteBuf.requestCapacity()
* [Java] prepare testBuilderGrowth() to fail again once FlexBuffersBuilder uses ByteBufferReadWriteBuf internally, add TestFail() as a better alternative to a plain "assert false"
* [Java] Revert some test changes and extract a small string that was used more than once; one could say three times, however, it might be worthy of a discussion if the third occasion also falls into this category, as it is an independent use case and thus would work in the same way even if the value changed.
Co-authored-by: Markus <markus@greenrobot>
To read and build flexbuffers on Java, one needs to wrap the data
using ByteBuffer. But for the common case of having ByteBuffers
backed by arrays, accessing from a ByteBuffer might be inefficient.
So this change introduces two interfaces: ReadBuf and ReadWriteBuf.
It allows one to read and writes data directly on an array. It also allow
other buffer implementations to be used with flexbuffers.
Another change is that FlexBuffersBuilder backed by array allows
the buffer to grow with the increase of the message size. Something
that could not be done with ByteBuffer.
