Improve gx deps dupes

[magik6k]

This makes gx deps dupes point at which packages are responsible for duplicate imports. For example this is output with broken go-resueport in go-ipfs:

package go-log imported with multiple hashes (mostly as QmcuXC5cxs79ro2cUuHs4HQ2bkDLJUYokwL8aivcX6HW3C):
        as QmcVVHfdyv15GVPk7NrxdWjh2hLVccXnoD8j2tyQShiXJb by go-reuseport
package gogo-protobuf imported with multiple hashes (mostly as QmdxUuburamoF6zF9qjeQC4WYcWGbWuRmdLacMEsW8ioD8):
        as QmZ4Qi3GaRbjcx28Sme5eMH7RQjGkt8wHxt2a65oLaeFEV by go-log
package go-logging imported with multiple hashes (mostly as QmQvJiADDe7JR4m968MwXobTCCzUqQkP87aRHe29MEBGHV):
        as QmcaSwFc5RBg8yCq54QURwEU4nwjfCpjbpmaAm4VbdGLKv by go-log

[Stebalien]

Thank you!