Change ModuleNameDbContext to IModuleNameDbContext in custom repositories

[gdlcf88]

After this change, customized EfCoreDbContext is supported.

See:

• https://docs.abp.io/en/abp/latest/Entity-Framework-Core#set-base-dbcontext-class-or-interface-for-default-repositories
• abpframework/abp#1429 (comment)
• EasyAbp/WeChatManagement#6

[gdlcf88]

Done.