Improve Consorsbank PDF-Importer and support exDate (#5765)

- Rename addDividendeTransaction() to addDividendTransaction() to follow English naming convention
- Add missing @Formatter:off/on around BUY→SELL type-switch comment
- Remove two WHAT-comments // Formatting some notes in addAccountStatementTransaction()
- Convert all ~70 test methods from legacy stream/cast format (SecurityItem.class::isInstance, BuySellEntryItem, Values.Amount.factorize, Money.of, LocalDateTime.parse, assertNull) to modern Hamcrest matchers
  (security(...), purchase(...), sale(...), dividend(...), taxes(...), deposit(...), removal(...), interest(...), interestCharge(...))
- Add missing hasExDate(null) to all dividend assertions
- Fix hasShares(0) → hasShares(0.00) to use double literals for zero amounts
- Remove unused imports and add required matcher imports; file reduced from 5471 to ~4200 lines
- Add exDate support

Author: Nirus2000