New Document Activity Cost created.

In TL - billing rate and internal rate added
In Project - total expense claim and total activity cost. Buttons addded - show time logs and show expense claims.
In Expense Claim - Employee and project link added. update cost in project on submit and on trash. Validation added to check sanctioned amount is not greater than claim amount.

erpnext/config/projects.py

@@ -32,6 +32,11 @@ def get_data():
 					"name": "Activity Type",
 					"description": _("Types of activities for Time Sheets"),
 				},
+				{
+					"type": "doctype",
+					"name": "Activity Cost",
+					"description": _("Cost of various activities"),
+				},
 			]
 		},
 		{