Move PageLoadTests to PerformanceTests/PageLoad

Move PageLoadTests to PerformanceTests/PageLoad
https://bugs.webkit.org/show_bug.cgi?id=51771

Rubber-stamped by Eric Seidel.

Actually move the directory.

* PageLoadTests: Removed.
* PageLoadTests/svg: Removed.
* PageLoadTests/svg/LICENSES: Removed.
* PageLoadTests/svg/files: Removed.
* PageLoadTests/svg/files/33041-Samurai.svg: Removed.
* PageLoadTests/svg/files/42450-under the see.svg: Removed.
* PageLoadTests/svg/files/42470-flower_from_my_garden_v2.svg: Removed.
* PageLoadTests/svg/files/44057-drops on a blade.svg: Removed.
* PageLoadTests/svg/files/Harvey_Rayner.svg: Removed.
* PageLoadTests/svg/files/az-lizard_benji_park_01.svg: Removed.
* PageLoadTests/svg/files/bamboo_01.svg: Removed.
* PageLoadTests/svg/files/cacuts_01.svg: Removed.
* PageLoadTests/svg/files/cowboy.svg: Removed.
* PageLoadTests/svg/files/crawfish2_ganson.svg: Removed.
* PageLoadTests/svg/files/deb9frac1.svg: Removed.
* PageLoadTests/svg/files/food_leif_lodahl_01.svg: Removed.
* PageLoadTests/svg/files/france.svg: Removed.
* PageLoadTests/svg/files/francobollo_gnome_ezechi_02.svg: Removed.
* PageLoadTests/svg/files/gearflowers.svg: Removed.
* PageLoadTests/svg/files/hereGear4.svg: Removed.
* PageLoadTests/svg/files/mtsthelens.svg: Removed.
* PageLoadTests/svg/files/mtsthelens0.jpg: Removed.
* PageLoadTests/svg/files/world-iso.svg: Removed.
* PageLoadTests/svg/files/worldcup.svg: Removed.
* PageLoadTests/svg/svg.pltsuite: Removed.
* PerformanceTests/PageLoad: Copied from PageLoadTests.
* Sources/cmake/WebKitPackaging.cmake:

PerformanceTests/PageLoad:

Update URLs to point to the new directory name.

* svg/svg.pltsuite:

Tools:

Update references to PageLoadTests to point to the new location.

* Scripts/run-pageloadtest:
* Scripts/webkitpy/common/config/build.py:

Websites/bugs.webkit.org:

Update list of top-level open-source directories.

* PrettyPatch/PrettyPatch.rb:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@74823 268f45cc-cd09-0410-ab3c-d52691b4dbfc