[lldb/bindings] Add Python ScriptedProcess base class to lldb module

In order to facilitate the writting of Scripted Processes, this patch
introduces a `ScriptedProcess` python base class in the lldb module.

The base class holds the python interface with all the - abstract -
methods that need to be implemented by the inherited class but also some
methods that can be overwritten.

This patch also provides an example of a Scripted Process with the
`MyScriptedProcess` class.

rdar://65508855

Differential Revision: https://reviews.llvm.org/D95712

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>

lldb/test/API/functionalities/scripted_process/TestScriptedProcess.py

@@ -0,0 +1,45 @@
+"""
+Test python scripted process in lldb
+"""
+
+import os
+
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+from lldbsuite.test import lldbtest
+
+
+class PlatformProcessCrashInfoTestCase(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+
+    def setUp(self):
+        TestBase.setUp(self)
+        self.source = "main.c"
+
+    def tearDown(self):
+        TestBase.tearDown(self)
+
+    def test_python_plugin_package(self):
+        """Test that the lldb python module has a `plugins.scripted_process`
+        package."""
+        self.expect('script import lldb.plugins',
+                    substrs=["ModuleNotFoundError"], matching=False)
+
+        self.expect('script dir(lldb.plugins)',
+                    substrs=["scripted_process"])
+
+        self.expect('script import lldb.plugins.scripted_process',
+                    substrs=["ModuleNotFoundError"], matching=False)
+
+        self.expect('script dir(lldb.plugins.scripted_process)',
+                    substrs=["ScriptedProcess"])
+
+        self.expect('script from lldb.plugins.scripted_process import ScriptedProcess',
+                    substrs=["ImportError"], matching=False)
+
+        self.expect('script dir(ScriptedProcess)',
+                    substrs=["launch"])
+