Tagged release v3.21.0

cf6006bd Forbid to activate TMA bid without x_nonSanctionedStatement doc
2667f255 remove_additionalIdentifiers
22d8fffc Apply suggestion to specs/timber-multiawards-initial-auction.yml
aee18657 Apply suggestion to specs/timber-multiawards-initial-auction-manual.yml
aa31873c Add tests for TMA custom types
6718feb8 Add custom procedure specs for timber multiawards
387f50db Allow to qualify single bid
4424fba6 Add tests for TMA active qualification state
a7d4b323 Implement TMA qualification state
6bb03abf Add default option for TMA award
1824d3dc Add tests for bid.quantity validation
ae3f60b5 Override tendering state for TMA procedure to validate bid quantity
eace4a99 Add method to validate bid.quantity for TMA procedure
5af07a1d Add tests on rectification and tendering for timber multiawards
c3103d32 Add new fixtures for timber multi awards procedure
7c90e812 Add models and base procdeure class for timber multiawards
511333e0 Add timber multiawards base spec
21374324 Add description to value field in timber-english.Contract model
b3d437b5 Add tests
309ca25f Add hidding of invalid auction bids if procedure status unsuccessful for railwayCargo dutch