Increase initial buffer size for `stroom.data.store.impl.fs.standard.BlockGZIPOutputFile`

[at055612]

Currently stroom.data.store.impl.fs.standard.BlockGZIPOutputFile has two underlying BlockByteArrayOutputStreams each of which is initialised with a byte[] of size 32 bytes. Each time there is insufficient space in the byte[], ByteArrayOutputStream will create a new byte[] double the size and array copy the contents over. At most the byte[] will be the Block GZip block size (1_000_000). For most Event and Raw Event streams, it will hit this limit. It will take 15 array copies to get from 32bytes to 1_000_000bytes.

It would be better to initialise the BlockByteArrayOutputStreams with a more appropriate intial size. The initial size is largely dependant on stream type, so this is best done in stroom.data.store.impl.fs.standard.FsPathHelper#getOutputStream. We could have a stroom prop that is a Map<String, Integer> (streamType => intitialSize).

Events and Raw Events could probably had a default prop value of 1_000_000, while Meta & Errors,

Based on looking at the file sizes in a stroom env, the default prop values could be:

• Raw Events - 1_000_000
• Raw Reference - 500_000
• Events - 1_000_000
• Reference - 500_000
• Records - 8_192
• Detections - 8_192
• Errors - 1_024
• Meta - 1_024
• Context - 1_024

And for the index buffer for writing the

        this.indexBuffer = new BlockByteArrayOutputStream();

This should probably use 8_192.