Move agama-network into agama-dbus-server

[imobachgs]

Move the network service, implemented in agama-network, to the agama-dbus-server package. All the code is kept under a new network module.

[coveralls]

Pull Request Test Coverage Report for Build 5345642365

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 76.83%

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Totals
Change from base Build 5345616913:	0.0%
Covered Lines:	5644
Relevant Lines:	7102

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💛 - Coveralls

[mvidner]

In other words, the agama-network crate is swallowed by the agama-dbus-server crate where it becomes a network module.
We do this because too many packages/crates do not make sense, we don't need them for dependency/governance reasons like other projects do.