[Bug]: Giant psbts cause crash

[Kukks]

What is your BTCPay version?

latest

How did you deploy BTCPay Server?

n/a

What happened?

500 error

How did you encounter this bug?

create a massive psbt using the wallet send

Relevant log output

System.IO.InvalidDataException: Form key length limit 2048 or value length limit 4194304 exceeded.
   at Microsoft.AspNetCore.WebUtilities.FormPipeReader.ThrowKeyOrValueTooLargeException()
   at Microsoft.AspNetCore.WebUtilities.FormPipeReader.ParseValuesSlow(ReadOnlySequence`1& buffer, KeyValueAccumulator& accumulator, Boolean isFinalBlock)
   at Microsoft.AspNetCore.WebUtilities.FormPipeReader.ParseFormValues(ReadOnlySequence`1& buffer, KeyValueAccumulator& accumulator, Boolean isFinalBlock)
   at Microsoft.AspNetCore.WebUtilities.FormPipeReader.ReadFormAsync(CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Http.Features.FormFeature.InnerReadFormAsync(CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Http.Features.FormFeature.ReadForm()
   at BTCPayServer.Security.SecurityExtensions.GetImplicitStoreId(HttpContext httpContext) in /source/BTCPayServer/Security/SecurityExtensions.cs:line 38
   at BTCPayServer.Security.CookieAuthorizationHandler.HandleRequirementAsync(AuthorizationHandlerContext context, PolicyRequirement requirement) in /source/BTCPayServer/Security/CookieAuthorizationHandler.cs:line 69
   at Microsoft.AspNetCore.Authorization.AuthorizationHandler`1.HandleAsync(AuthorizationHandlerContext context)
   at Microsoft.AspNetCore.Authorization.DefaultAuthorizationService.AuthorizeAsync(ClaimsPrincipal user, Object resource, IEnumerable`1 requirements)
   at Microsoft.AspNetCore.Authorization.Policy.PolicyEvaluator.AuthorizeAsync(AuthorizationPolicy policy, AuthenticateResult authenticationResult, HttpContext context, Object resource)
   at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
   at BTCPayServer.Hosting.BTCPayMiddleware.Invoke(HttpContext httpContext) in /source/BTCPayServer/Hosting/BTCpayMiddleware.cs:line 97
   at BTCPayServer.Hosting.GreenfieldMiddleware.Invoke(HttpContext httpContext) in /source/BTCPayServer/Hosting/GreenfieldMiddleware.cs:line 30
   at Microsoft.AspNetCore.Diagnostics.StatusCodePagesMiddleware.Invoke(HttpContext context)
   at BTCPayServer.Hosting.HeadersOverrideMiddleware.Invoke(HttpContext httpContext) in /source/BTCPayServer/Hosting/HeadersOverrideMiddleware.cs:line 29
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ProcessRequests[TContext](IHttpApplication`1 application)

What browser do you use?

No response

Additional information

No response

Are you sure this is a bug report?

• I confirm this is a bug report