Custom Db Schema for SqlServer, PostgreSql and Oracle

[gersti07]

This PR allows you to define a custom DB Schema in V2. This basically merges this #4638 in V2.

Defining a custom Schema:

 elsa.UseWorkflowManagement(management => { management.UseEntityFrameworkCore(ef =>
        ef.UseSqlServer("Server=(localdb)\\MSSQLLocalDb;Initial Catalog=Elsav3CustomSchema;Integrated Security=True;",
        new ElsaDbContextOptions()
        {
            SchemaName = "CustomSchemaName",
        }));
    });

If no Custom-Schema is defined, Elsa will be used.

This change applies to

• SqlServer
• PostgreSql
• Oracle
• MySql

[gersti07]

@dotnet-policy-service agree company="MMI MUNICH MEDIA INTELLIGENCE GmbH"

[gerstiatmmi]

@dotnet-policy-service agree company="MMI MUNICH MEDIA INTELLIGENCE GmbH"

[sfmskywalker]

Thanks!