【BugFix/lib.d.ts】fix constructor in URLSearchParams

[kgtkr]

Fixes #15338

[msftclas]

All CLA requirements met.

[ikatyang]

from https://github.com/Microsoft/TypeScript/tree/master/src/lib#readme:

Generated files

Any files ending in .generated.d.ts aren't mean to be edited by hand.
If you need to make changes to such files, make a change to the input files for our library generator.

[mhegazy]

Thanks for your PR. As @ikatyang mentioned, these files are not manually edited, they are auto-generated from a script in . You can find more information about contributing lib.d.ts fixes at https://github.com/Microsoft/TSJS-lib-generator.

Changes should be done in https://github.com/Microsoft/TSJS-lib-generator instead.

Please find more information at: https://github.com/Microsoft/TypeScript/blob/master/CONTRIBUTING.md#contributing-libdts-fixes.