cargo: Added egui crate

Summary:
Added `egui` crate to fbsource vendoring.

NOTE: I had to add the `profiling` crate because of emilk/egui#5491

Differential Revision: D68569632

fbshipit-source-id: 587a06ce744e3441de64c19b350606b3eee924f5

Cargo.toml

@@ -11,6 +11,7 @@ imgui-sys = { git = "https://github.com/imgui-rs/imgui-rs.git", rev = "2abba18c0
 lru-disk-cache = { git = "https://github.com/mozilla/sccache", rev = "fdbf843d174c6796d736b2b61dab0297670390f8" }
 perf-event = { version = "0.4", git = "https://github.com/krallin/perf-event.git", rev = "86224a9bc025d5d19f719542f27c8c629a08b167" }
 perf-event-open-sys = { version = "4.0", git = "https://github.com/krallin/perf-event.git", rev = "86224a9bc025d5d19f719542f27c8c629a08b167" }
+profiling = { version = "1.0.16", git = "https://github.com/aclysma/profiling.git", rev = "1b3e20c8e59eddbb6ae0d64fff849d07a903dd0c" }
 pyo3-build-config = { package = "pyo3-build-config", version = "0.21.2", git = "https://github.com/fbsource/pyo3", rev = "ff94a09031cc29d88d57ae3c846e5b871497aeb9" }
 quickcheck = { git = "https://github.com/jakoschiko/quickcheck", rev = "6ecdf5bb4b0132ce66670b4d46453aa022ea892c" }
 uefisettings = { git = "https://github.com/linuxboot/uefisettings", rev = "f16daed1d2bd1216204fd24e876c6477d03aebb3" }