Merge bitcoin/bitcoin#23006: multiprocess: Add new bitcoin-gui, bitcoin-qt, bitcoin-wallet init implementations

d5f985e51f multiprocess: Add new bitcoin-gui, bitcoin-qt, bitcoin-wallet init implementations (Russell Yanofsky)

Pull request description:

  Add separate `interfaces::Init` subclasses for `bitcoin-wallet`,  `bitcoin-gui`, and `bitcoin-qt` binaries instead of sharing `bitcoind` and `bitcoin-node` init subclasses in different binaries. After this, the new init subclasses can be customized in #10102, so node and wallet code is dropped from the `bitcoin-gui` binary and wallet code is dropped from into the `bitcoin-node` binary.

  ---

  This PR is part of the [process separation project](https://github.com/bitcoin/bitcoin/projects/10).

ACKs for top commit:
  lsilva01:
    reACK d5f985e
  hebasto:
    re-ACK d5f985e51f, only suggested changes since my [previous](https://github.com/bitcoin/bitcoin/pull/23006#pullrequestreview-787537444) review.

Tree-SHA512: 6784210bd9ce3a6fbc66852680d0e9bc513c072dc538aeb7f48cb6a41580d3f567ccef04f975ee767a714a4b05d4d87273e94a79abda1b9c25d5ac4bbe752006

build_msvc/bitcoin-qt/bitcoin-qt.vcxproj

@@ -9,7 +9,7 @@
   </PropertyGroup>
   <ItemGroup>
     <ClCompile Include="..\..\src\qt\main.cpp" />
-    <ClCompile Include="..\..\src\init\bitcoind.cpp" />
+    <ClCompile Include="..\..\src\init\bitcoin-qt.cpp" />
     <ResourceCompile Include="..\..\src\qt\res\bitcoin-qt-res.rc" />
   </ItemGroup>
   <ItemGroup>

build_msvc/bitcoin-wallet/bitcoin-wallet.vcxproj

@@ -10,6 +10,9 @@
   </PropertyGroup>
   <ItemGroup>
     <ClCompile Include="..\..\src\bitcoin-wallet.cpp" />
+    <ClCompile Include="..\..\src\init\bitcoin-wallet.cpp">
+      <ObjectFileName>$(IntDir)init_bitcoin-wallet.obj</ObjectFileName>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\libbitcoinconsensus\libbitcoinconsensus.vcxproj">

build_msvc/test_bitcoin-qt/test_bitcoin-qt.vcxproj

@@ -8,7 +8,7 @@
     <OutDir>$(SolutionDir)$(Platform)\$(Configuration)\</OutDir>
   </PropertyGroup>
   <ItemGroup>
-    <ClCompile Include="..\..\src\init\bitcoind.cpp" />
+    <ClCompile Include="..\..\src\init\bitcoin-qt.cpp" />
     <ClCompile Include="..\..\src\test\util\setup_common.cpp" />
     <ClCompile Include="..\..\src\qt\test\addressbooktests.cpp" />
     <ClCompile Include="..\..\src\qt\test\apptests.cpp" />