[linker-analyzer] added --flat option (#5629)

[linker-analyzer] added --flat option (#5629)

* [linker-analyzer] added --flat option

This options allows to see all dependencies per vertex at once, with
displayed distance in the graph between the vertex and dependent
vertex.

An example of flat output:

    Loading dependency tree from: linker-dependencies.xml.gz

    --- Type dependencies: 'Android.App.Activity' --------------------------

    Distance | TypeDef:Android.App.Activity [total deps: 7]
    ------------------------------------------------------------------------
           1 | TypeDef:XA.App.MainActivity
           2 | Assembly:XA.App, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null
           3 | Other:Mono.Linker.Steps.ResolveFromAssemblyStep
           3 | Other:Mono.Tuner.CustomizeActions
           3 | Other:MonoDroid.Tuner.MonoDroidMarkStep
           2 | TypeDef:XA.App.MainActivity/<>c__DisplayClass1_0

* [linker-analyzer] Get back to using "unnamed" tuples

Use unnamed tuples to workaround mcs bug. We can revert this change,
once mcs is updated.

The build with mcs was failing like this, because of mcs bug:

```
MacBook:linker-analyzer rodo$ make
/Applications/Xcode.app/Contents/Developer/usr/bin/make all-local
MCS     [net_4_x-darwin] linkeranalyzer.exe

Unhandled Exception:
System.NotImplementedException: named tuples for .interfaceimpl
  at Mono.CSharp.TypeDefinition.Emit () [0x00028] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.ClassOrStruct.Emit () [0x00025] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.TypeDefinition.Emit () [0x002e8] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.ClassOrStruct.Emit () [0x00025] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.Class.Emit () [0x00000] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.TypeDefinition.EmitContainer () [0x0000f] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.TypeContainer.EmitContainer () [0x0001e] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.NamespaceContainer.EmitContainer () [0x00007] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.TypeContainer.EmitContainer () [0x0001e] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.NamespaceContainer.EmitContainer () [0x00007] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.TypeContainer.EmitContainer () [0x0001e] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.ModuleContainer.EmitContainer () [0x0009c] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.AssemblyDefinition.Emit () [0x00098] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.AssemblyDefinitionStatic.Emit () [0x00126] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.Driver.Compile () [0x002f3] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.Driver.Main (System.String[] args) [0x00052] in <e953cb7042ea446195951c3e14c2cc5a>:0
[ERROR] FATAL UNHANDLED EXCEPTION: System.NotImplementedException: named tuples for .interfaceimpl
  at Mono.CSharp.TypeDefinition.Emit () [0x00028] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.ClassOrStruct.Emit () [0x00025] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.TypeDefinition.Emit () [0x002e8] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.ClassOrStruct.Emit () [0x00025] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.Class.Emit () [0x00000] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.TypeDefinition.EmitContainer () [0x0000f] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.TypeContainer.EmitContainer () [0x0001e] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.NamespaceContainer.EmitContainer () [0x00007] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.TypeContainer.EmitContainer () [0x0001e] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.NamespaceContainer.EmitContainer () [0x00007] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.TypeContainer.EmitContainer () [0x0001e] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.ModuleContainer.EmitContainer () [0x0009c] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.AssemblyDefinition.Emit () [0x00098] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.AssemblyDefinitionStatic.Emit () [0x00126] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.Driver.Compile () [0x002f3] in <e953cb7042ea446195951c3e14c2cc5a>:0
  at Mono.CSharp.Driver.Main (System.String[] args) [0x00052] in <e953cb7042ea446195951c3e14c2cc5a>:0
make[1]: *** [../../class/lib/net_4_x-darwin/linkeranalyzer.exe] Error 1
make: *** [do-all] Error 2

```