Little optimization with BinaryData in TextPartitionHandler

[marcominerva]

@dluc Before making a PR, I'm asking here because, based on the comment, I don't know if you have already tried. The following check:

kernel-memory/service/Core/Handlers/TextPartitioningHandler.cs

Lines 122 to 123 in ad4a996

	// Skip empty partitions. Also: partitionContent.ToString() throws an exception if there are no bytes.
	if (partitionContent.ToArray().Length == 0) { continue; }

Could be replaced with partitionContent.Length == 0 or partitionContent.IsEmpty? In this way, we avoid a copy.

[dluc]

good idea 👍

[marcominerva]

Done: #889