Rename CoverageLineData to TestLocation (#1)

As part of #1164, for more information see the TODOs in https://github.com/infection/infection/blob/4ce9b86d0f6eeabab6d9ea991b62858ba2e3736c/src/TestFramework/Coverage/TestLocations.php

BC breaks:

- Rename `CoverageLineData` to `TestLocation`
- Rename `CoverageLineData::withMethod()` to `TestLocation::forMethod()`
- Remove `CoverageLineData::with()` in favour of `TestLocation::__construct()`
- Make the properties of `CoverageLineData` private and provide public accessors instead
- Remove `TestFrameworkAdapter::JUNIT_FILE_NAME`

.gitignore

@@ -2,3 +2,4 @@
 /.idea
 /.php_cs.cache
 /vendor/
+/.composer.lock

composer.json

@@ -10,15 +10,24 @@
         }
     ],
     "config": {
-    "platform": {
-        "php": "7.2.9"
+        "sort-packages": true
     },
-    "sort-packages": true
-},
+
     "autoload": {
         "psr-4": {
             "Infection\\AbstractTestFramework\\": "src/"
         }
     },
-    "require": {}
+    "autoload-dev": {
+        "psr-4": {
+            "Infection\\AbstractTestFramework\\": "tests/"
+        }
+    },
+
+    "require": {
+        "php": "^7.3"
+    },
+    "require-dev": {
+        "phpunit/phpunit": "^9.0"
+    }
 }