Optimize for VSCode C++ extension file scan (#27245)
### Description
Update the settings for VSCode C++ extension to reduce the file
scanning. (potentially extend the life of the SSD on the devbox)
Added a few common folders into the exclusion list to help reduce the
time of file scanning.
### Motivation and Context
By default the VSCode C++ extension will scan all folders in the
workspace unless it's excluded. This will cause the default build folder
being scanned, which contains 100k+ files and 20k+ C++ source files for
a WebGPU build.
A simple analyze of my local workspace:
```
Folder Exists Total Files C++ Files Top Extensions
----------------------------------------------------------------------------------------------------
build_webgpu Yes 255.4K 36.1K .cpp:14084, .h:12229, .cc:6548, .c:2569, .hpp:257
build Yes 167.2K 26.3K .h:11012, .cpp:8448, .cc:3899, .c:1689, .hpp:611
build_wasm_inferencing_webgpu Yes 130.0K 17.8K .cpp:6994, .h:6040, .cc:3183, .c:1285, .hpp:124
cmake Yes 27.9K 7.0K .h:3561, .c:2601, .cpp:587, .cc:119, .inc:43
cmake/external Yes 27.8K 6.9K .h:3557, .c:2600, .cpp:587, .cc:119, .inc:43
build_jsep Yes 17.8K 4.4K .h:1618, .cpp:1515, .cc:1006, .c:127, .hpp:88
onnxruntime Yes 6.5K 4.1K .cc:2002, .h:1840, .cpp:273, .inc:21, .hpp:3
orttraining Yes 812 563 .cc:289, .h:268, .hpp:4, .cpp:2
winml Yes 341 224 .h:149, .cpp:75
include Yes 123 121 .h:121
js Yes 52.4K 43 .h:26, .cc:8, .cpp:7, .c:2
objectivec Yes 51 22 .h:22
java Yes 128 21 .c:20, .h:1
csharp Yes 385 1 .cpp:1
.git Yes 3.3K 1 .cc:1
rust Yes 39 0 -
dockerfiles Yes 13 0 -
docs Yes 76 0 -
tools/ci_build Yes 307 0 -
samples Yes 15 0 -
----------------------------------------------------------------------------------------------------
```
