Implement code coverage tool (#1390)

* Implement code coverage tool

* Switch to solution style of running tests

* Add shell version of coverage file

* Fix formatting in coverage.sh

* Add trailing newline to powershell

test/coverage.ps1

@@ -0,0 +1,31 @@
+param(
+    [string][Alias('c')]$Configuration = "Release",
+    [string][Alias('o')]$Output = "CoverageOutput",
+    [string][Alias('rt')]$ReportType = "lcov"
+)
+
+function Install-Tools {
+    dotnet tool restore
+}
+
+function Print-Environment {
+    dotnet --version
+}
+
+function Prepare-Output {
+    if (Test-Path -Path $Output) {
+        Remove-Item $Output -Recurse
+    }
+}
+
+function Run-Tests {
+    dotnet test $PSScriptRoot/bitwarden.tests.sln /p:CoverletOutputFormatter="cobertura" --collect:"XPlat Code Coverage" --results-directory:"$Output" -c $Configuration
+
+    dotnet tool run reportgenerator -reports:$Output/**/*.cobertura.xml -targetdir:$Output -reporttypes:"$ReportType"
+}
+
+Write-Host "Collecting Code Coverage"
+Install-Tools
+Print-Environment
+Prepare-Output
+Run-Tests