fix(csharp): Modify method name to PascalCase, simplify new expression (#840)

* Modify method name to PascalCase(array and linked list)

* Modify method name to PascalCase(backtracking)

* Modify method name to PascalCase(computational complexity)

* Modify method name to PascalCase(divide and conquer)

* Modify method name to PascalCase(dynamic programming)

* Modify method name to PascalCase(graph)

* Modify method name to PascalCase(greedy)

* Modify method name to PascalCase(hashing)

* Modify method name to PascalCase(heap)

* Modify method name to PascalCase(searching)

* Modify method name to PascalCase(sorting)

* Modify method name to PascalCase(stack and queue)

* Modify method name to PascalCase(tree)

* local check

docs/zh/chapter_greedy/fractional_knapsack_problem.md

@@ -58,7 +58,7 @@
     ```csharp title="fractional_knapsack.cs"
     [class]{Item}-[func]{}
 
-    [class]{fractional_knapsack}-[func]{fractionalKnapsack}
+    [class]{fractional_knapsack}-[func]{FractionalKnapsack}
     ```
 
 === "Go"

docs/zh/chapter_greedy/greedy_algorithm.md

@@ -40,7 +40,7 @@
 === "C#"
 
     ```csharp title="coin_change_greedy.cs"
-    [class]{coin_change_greedy}-[func]{coinChangeGreedy}
+    [class]{coin_change_greedy}-[func]{CoinChangeGreedy}
     ```
 
 === "Go"

docs/zh/chapter_greedy/max_capacity_problem.md

@@ -99,7 +99,7 @@ $$
 === "C#"
 
     ```csharp title="max_capacity.cs"
-    [class]{max_capacity}-[func]{maxCapacity}
+    [class]{max_capacity}-[func]{MaxCapacity}
     ```
 
 === "Go"

docs/zh/chapter_greedy/max_product_cutting_problem.md

@@ -84,7 +84,7 @@ $$
 === "C#"
 
     ```csharp title="max_product_cutting.cs"
-    [class]{max_product_cutting}-[func]{maxProductCutting}
+    [class]{max_product_cutting}-[func]{MaxProductCutting}
     ```
 
 === "Go"