CDMS-179 optimises Movements ByItemCount analytics for bigger datasets

[craigedmunds]

No description provided.

[github-actions]

Package	Line Rate	Branch Rate	Health
Btms.Business	73%	44%	➖
Btms.Emf	11%	6%	❌
Btms.Types.Gvms.Mapping	38%	26%	❌
Btms.Metrics	82%	0%	✔
Btms.Types.Gvms	67%	100%	➖
Btms.Types.Alvs.Mapping	74%	0%	➖
Btms.Types.Ipaffs.Mapping	73%	33%	➖
Btms.Azure	43%	75%	❌
Btms.BlobService	31%	17%	❌
Btms.Backend	56%	57%	❌
Btms.Analytics	84%	62%	✔
Btms.Backend.Data	65%	61%	➖
Btms.Consumers	75%	56%	➖
Btms.Common	75%	17%	➖
Btms.Model	91%	93%	✔
Btms.SyncJob	81%	71%	✔
Btms.SensitiveData	80%	83%	✔
Btms.Types.Ipaffs	94%	56%	✔
Btms.Types.Alvs.Mapping.V1.Tests	0%	0%	❌
Btms.Types.Alvs	83%	0%	✔
TestDataGenerator	58%	47%	❌
Summary	73% (5685 / 7801)	49% (458 / 943)	➖