source generators for packet (de-)serialization

[MeikelLP]

This is just a new foundation for the networking in this project which may be improved even further.

Benefits of source generator:

• Transparent behaviour
• Debuggability
• Performance

But this doesn't come without a cost:

• The maintenance may be much harder for newcomers than classic reflection
• The project must be changed heavily in order to integrate this new networking stack
• It may look like even more magic than reflection from outside
• Tests currently are very verbose and hard to maintain

Dependencies

• Upgrades to .NET 7

• 9

Performance

Tested with

• DamageInfo as outgoing (serialize)
• Attack as incoming (deserialize)

BenchmarkDotNet=v0.13.5, OS=Windows 10 (10.0.19045.2965/22H2/2022Update)
Intel Core i9-9900K CPU 3.60GHz (Coffee Lake), 1 CPU, 16 logical and 8 physical cores
.NET SDK=7.0.105
[Host]     : .NET 7.0.5 (7.0.523.17405), X64 RyuJIT AVX2
DefaultJob : .NET 7.0.5 (7.0.523.17405), X64 RyuJIT AVX2

Method	Mean	Error	StdDev	Gen0	Allocated
Deserialize_PacketDetails	350.00 ns	4.335 ns	3.620 ns	0.0687	576 B
Deserialize_SourceGenerator	17.84 ns	0.408 ns	0.797 ns	0.0115	96 B
Serialize_PacketDetails	1,131.35 ns	21.458 ns	22.035 ns	0.0515	440 B
Serialize_SourceGenerator	12.32 ns	0.114 ns	0.107 ns	0.0048	40 B