This PR removes a lot of unnecessary uses of `EXPECT_STREQ` combined
with calls to `c_str()`, and converts these comparisons simply to
`std::string` comparisons using `EXPECT_EQ`. This is functionally the
same, but it is arguably easier to read in general.
Resolves https://github.com/brave/brave-browser/issues/46600
cdesouza-chromium
4a41889aca