[Add] utils\export_fig

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>
[Change] selrulecounts graphs cut to 50-100%

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>
[Fix] selecttrades: Volume instead of size

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>
[Change] Big revision for Analyze selection, cleaning and sampling #01

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>