False positives for various legal terms

## Description

The following terms are being falsely flagged as errors:

**Common abbreviations**
[IBAN](https://en.wikipedia.org/wiki/International_Bank_Account_Number)
[EBITDA](https://en.wikipedia.org/wiki/Earnings_before_interest,_taxes,_depreciation_and_amortization)
[LIBOR](https://en.wikipedia.org/wiki/Libor)
[TARGET2](https://en.wikipedia.org/wiki/TARGET2)
[GDPR](https://en.wikipedia.org/wiki/General_Data_Protection_Regulation)
[EU](https://en.wikipedia.org/wiki/European_Union)
[EEA](https://en.wikipedia.org/wiki/European_Economic_Area)
[TEU](https://en.wikipedia.org/wiki/Treaty_on_European_Union)
[TFEU](https://en.wikipedia.org/wiki/Treaty_on_the_Functioning_of_the_European_Union)
[CZK](https://en.wikipedia.org/wiki/Czech_koruna) and relatedly [heller](https://en.wiktionary.org/wiki/heller)

**Selected legal terms**
transferees
intercreditor
multicurrency
sublicense
bailment
[witnesseth](https://www.cobrief.app/resources/legal-glossary/now-this-agreement-witnesseth-overview-definition-and-example/)
derogations _(Harper suggests singular, but it can be in plural as well)_

**Latin terms, used commonly in English (not sure what is the intended behaviour here)**
per annum
de minimis
[mutatis mutandis](https://en.wikipedia.org/wiki/Mutatis_mutandis)
[Per definitionem](https://www.oxfordreference.com/abstract/10.1093/acref/9780195369380.001.0001/acref-9780195369380-e-1591)
pro rata
per se
inter alia
de iure / de jure
vis-à-vis _(French, not Latin)_

Other common Latinisms (per Kenneth Adams, A Manual of Style for Contract Drafting) include:
bona fide
contra proferentem
in personam
ipso facto
pari passu
per diem
prima facie
sui generis

## Resources

If the problem is not obvious, some online resources clarifying the relevant grammar point can be useful.

## Screenshots

If applicable, add screenshots to help explain the false positive.

Start by reproducing the listed terms in Harper and tracing which grammar or spelling check flags them. Clarify the intended treatment of the Latinisms, then update the relevant term handling and add regression coverage so legitimate legal terminology is no longer reported as an error.

Written by the indexing model from the issue text.