Support Fuzzier Searching using `navto`

[mjbvz]

From microsoft/vscode#20039
TypeScript Version: 2.1.5

function helloWorld1() {}
function hElloWorld2() {}
function helloWOrld3() {}
function hElloWOrld4() {}

Expected behavior
A search with eo in any capitalization returns some results. This is how VSCode's search works for symbols in a document

Actual Behavior
Using navTo on tsserver, only a search term of EO returns any results

[Trace - 2:27:05 PM] Sending request: navto (24). Response expected: yes. Current queue length: 0
Arguments: {
    "file": "/Users/matb/projects/sandy/y.ts",
    "searchValue": "EO"
}
[Trace - 2:27:05 PM] Response received: navto (24). Request took 2 ms. Success: true 
Result: [
    {
        "name": "hElloWOrld4",
        "kind": "function",
        "file": "/Users/matb/projects/sandy/y.ts",
        "start": {
            "line": 4,
            "offset": 1
        },
        "end": {
            "line": 4,
            "offset": 26
        },
        "matchKind": "camelCase"
    }
]

Here's the logic we use on the VSCode side for filtering: https://github.com/Microsoft/vscode/blob/master/src/vs/base/common/filters.ts#L355

I believe fuzzySeparateFilter is the key difference

[mhegazy]

Implementation proposals are welcome.