Change oav parameters direction attribute to enum from int

[rtuck99]

Changes OAVParameters so that direction attribute is of type ShutterState instead of int.

Required for

• Fix mx-bluesky against latest dodal mx-bluesky#1769

Instructions to reviewer on how to test:

1. Do thing x
2. Confirm thing y happens

Checks for reviewer

• Would the PR title make sense to a scientist on a set of release notes
• If a new device has been added does it follow the standards
• If changing the API for a pre-existing device, ensure that any beamlines using this device have updated their Bluesky plans accordingly
• Have the connection tests for the relevant beamline(s) been run via dodal connect ${BEAMLINE}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.14%. Comparing base (a979c80) to head (4b4ec54).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2092   +/-   ##
=======================================
  Coverage   99.14%   99.14%           
=======================================
  Files         344      344           
  Lines       13387    13388    +1     
=======================================
+ Hits        13273    13274    +1     
  Misses        114      114           

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[DominicOram]

Thanks, approving to get this over the line but there's some weird things going on here...

It feels like this should have been caught by a test in dodal but on further investigation direction is never used in dodal. Instead, setup_pin_tip_detection takes a direction and uses that. However, MX have their own setup_pin_tip_detection_params, which does use the direction. I think this is either a side-effect of when @noemifrisina split out the pin tip detection to be into dodal rather than mx-bluesky or when we were trying to get pin tip centring working on aithre. I suggest we try and combine these, I'll make an issue and investigate if I get time