feat: 291 switch to third party anonymisation

[peshence]

291 Switch from DIY DICOM anonymiasation to Kitware DICOM Anonymizer. In the process:

• Public DICOM tags now have default actions as per the library.
• old "hash" function applied to UIDs while keeping their prefix has been replaced with a random UID replacement (no prefix continuity) as we don't currently believe loading images on original scanner is likely.
• only patientID is now hashed via hasher api (as patientID+Acc_num). Previously Patient name and acc_num were also hased like this, now they are replaced as empty/constant strings in existing projects since they shouldn't be used for linking.
• removed date shifting options
• anonymisation and whitelisting now handle sequences

Possible improvement: Convert current YAMl tag configs to JSON to make use the the existing underlying action loading functionality. We can then do regex replacements and a few other slightly more complex actions. Not sure if it's necessary at this stage.

Possible risks: Private tags may change element number (from 0x10xx to 0x11xx e.g.) and we would not action on them (but they should be deleted by whitelist). There is also a very slight possibility in the future a tag has a keep action, but as another private creator existed upstream we keep the wrong tag, which may contain private data. Mitigation would be to specify private tags properly in our operations (so group, tag, creator) and then adjusting the tag actions accordingly for each dataset.

[peshence]

This is now ready for review. I have also updated the description, repeating risk here:

Possible risks: Private tags may change element number (from 0x10xx to 0x11xx e.g.) and we would not action on them (but they should be deleted by whitelist). There is also a very slight possibility in the future a tag has a keep action, but as another private creator existed upstream we keep the wrong tag, which may contain

Should I make a ticket or is this not something we are really worried about?