Introduce DefaultDbContextAttribute to set a default dbcontext

[hikalkan]

This can be useful in a multi dbcontext project to get default dbcontext if there are multiple dbcontext for given conditions.

[acjh]

aspnetboilerplate/src/Abp.EntityFramework.Common/DbContextTypeMatcher.cs

Lines 123 to 133 in 7691bdc

	filteredTypes = filteredTypes
	.Where(type => !type.GetTypeInfo().IsDefined(typeof(DefaultDbContextAttribute), true))
	.ToList();
	if (filteredTypes.Count == 1)
	{
	return filteredTypes[0];
	}
	throw new AbpException(string.Format(
	"Found more than one concrete type for given DbContext Type ({0}) define MultiTenancySideAttribute with {1}. Found types: {2}.",

Should that ! be removed?

Related: https://forum.aspnetboilerplate.com/viewtopic.php?p=28420

[hikalkan]

I think so. You can send a PR if you like :)