Migrate uses of GURL to url::Origin when possible

[mariospr]

Description

As explained in the Chromium documentation [1], "URLs are often not sufficient for security decisions, since the origin may not be present in the URL (e.g., about:blank), may be tricky to parse (e.g., blob: or filesystem: URLs), or may be opaque despite a normal-looking URL (e.g., the security context may be sandboxed)".

Unfortunately, Brave uses at the moment GURL in several places where url::Origin should be used instead (e.g. in brave::BraveRequestInfo::tab_origin, and other places), which is becoming an increasingly bigger problem as upstream Chromium is progressively migrating away from GURL as well.

Also, note that this not only affects C++ files but also mojo definitions as well, see for instance:

module brave_wallet.mojom;

[...]

interface EthJsonRpcController {
  AddEthereumChain(EthereumChain chain, url.mojom.Url origin) => (string chain_id, bool accepted);
  [...]
}

Thus, filing this issue to track down the effort of converting as much as possible to url::Origin instead of using GURL (and maybe cases using strings as well, such as this one).

In summary, as mentioned in [1], we should use the following datatypes to represent origins:

• C++: url::Origin or blink::SecurityOrigin (instead of GURL or blink::KURL).
• Mojo: url.mojom.Origin (instead of url.mojom.Url).
• Java: org.chromium.url.Origin (see also url::Origin::FromJavaObject and url::Origin::CreateJavaObject).

[1] https://chromium.googlesource.com/chromium/src/+/main/docs/security/origin-vs-url.md

[mariospr]

cc @pes10k @diracdeltas @iefremov @goodov

[pes10k]

cc @pilgrim-brave