Implementation of ]m [M ]m ]M

Please implement these:

From vim help:
The above four commands assume that the file contains a class with methods.
The class definition is surrounded in { and }. Each method in the class is also surrounded with { and }. This applies to the Java language. The file looks like this:

    // comment
    class foo {
            int method_one() {
                    body_one();
            }
            int method_two() {
                    body_two();
            }
    }

Starting with the cursor on body_two() using [m will jump to the { at the start of method_two() (obviously this is much more useful when the method is long!) .
Using 2[m will jump to the start of method_one().
Using 3[m will jump to the start of the class.

The issue names no source files or tests. Start by locating the TypeScript extension's existing motion and keybinding handling for [m, [M, ]m, and ]M, then compare its behavior with the linked Vim help. Done means the four commands support count-prefixed jumps to method or class boundaries as described.