LXT2 partial reads trade file size for selectivity

GTKWave documents LXT2 block-level random access and optional partial zip separation, which increases file size for faster large-trace access. Bybell's 2018 mailing-list explanation says partial mode picks chunks of signals rather than processing a whole block; the converter's time ordering is only monotonic within 2K-net groups. The manual also says vcd2lxt2 coalesces glitches, so size and speed results must not be treated as full event-preserving compression. These features do not establish superiority to FST: Bybell recommended FST in the same discussion, and current GTKWave docs list planned LXT2 removal for GTKWave 4.