Move booked/valued at dates from transaction to transfer

[VMelnalksnis]

It makes more sense to be on the transfer, since a transaction can have transfers which happened on different days

Changes proposed in this pull request:

• Move booked/valued at from transactions to transfers table
• Calculate the booked/valued at values on DetailedTransaction as the largest date from Transfers

[codecov]

Codecov Report

Merging #818 (dc8d408) into master (30a8893) will decrease coverage by 0.18%.
The diff coverage is 67.69%.

@@            Coverage Diff             @@
##           master     #818      +/-   ##
==========================================
- Coverage   75.18%   75.00%   -0.18%     
==========================================
  Files         345      345              
  Lines       10251    10234      -17     
==========================================
- Hits         7707     7676      -31     
- Misses       2544     2558      +14     

Impacted Files	Coverage Δ
...ia.Core/Transactions/Controls/TransactionRefund.cs	17.64% <ø> (+1.85%)	⬆️
...omeshade.WebApi.Models/Transactions/Transaction.cs	100.00% <ø> (ø)
....WebApi.Models/Transactions/TransactionCreation.cs	100.00% <ø> (ø)
...de.WebApi/V1/Controllers/TransactionsController.cs	96.63% <ø> (+1.43%)	⬆️
...ade.TestingHelpers/Models/TransactionExtensions.cs	100.00% <ø> (ø)
...ansactions/Transfers/TransferUpsertionViewModel.cs	42.99% <28.57%> (-5.76%)	⬇️
...Core/Transactions/TransactionUpsertionViewModel.cs	62.82% <50.00%> (-1.14%)	⬇️
...meshade.Avalonia.Core/DesignTime/DesignTimeData.cs	99.00% <100.00%> (ø)
...onia.Core/DesignTime/DesignTimeGnomeshadeClient.cs	73.73% <100.00%> (+0.16%)	⬆️
...ore/Transactions/Controls/TransactionProperties.cs	95.45% <100.00%> (-2.22%)	⬇️
... and 11 more