Allow dynamic choice of HTTP method

[lihaoyi]

Fixes #67
Fixes #52

This was always possible in a roundabout way via

requests.Requester("get", requests.Session()).apply("https://www.google.com")

But this PR adds a convenient alias and documents it for discoverability

requests.send("get")("https://www.google.com")

[lolgab]

@lihaoyi By looking at other tests:

diff --git a/requests/test/src/requests/RequestTests.scala b/requests/test/src/requests/RequestTests.scala
index 834eea5..72dd505 100644
--- a/requests/test/src/requests/RequestTests.scala
+++ b/requests/test/src/requests/RequestTests.scala
@@ -82,9 +82,9 @@ object RequestTests extends TestSuite{
 
         val res1 = requests.send("put")(
           "https://httpbin.org/put",
-          data = Map("hello" -> "world", "foo" -> "baz"),
+          data = new RequestBlob.FormEncodedRequestBlob(Map("hello" -> "world", "foo" -> "baz")),
           chunkedUpload = true
-        ).text
+        ).text()
 
         assert(read(res1).obj("form") == Obj("foo" -> "baz", "hello" -> "world"))
       }

Maybe it's some limitation that can be removed, but not in this PR for sure.

[lihaoyi]

@lolgab afaict it's a bug in the scala3 compiler, so I'm fine skipping that test in scala3 for now. The chance of us causing scala3-specific bugs is rather low, and if the bug is on the scala3 side it's their responsibility to fix rather than ours

[lolgab]

the .text requiring () is because Scala 3 makes a difference between methods declared like:

def text: String

and if declared like:

def text(): String

as it happens here.

About new FormEncodedRequestBlob() being required, it is probably because Scala 3 doesn't automatically lift implicit parameters into implicit conversions as Scala 2 does.

My 2 cents:
The other tests are written like this and I don't see a reason for send to be special enough to have a src-2 test.
This Scala2/Scala3 source incompatibility should be a open issue instead with the reproduction we want to behave coherently in Scala 2 and Scala 3 and which doesn't today.

[lihaoyi]

.text vs .text() is trivial to fix, but the other is clearly a bug. The fact that the other tests call it with an explicit new RequestBlob.FormEncodedRequestBlob means the other tests are wrong. The correct thing to do is rely on the implicit conversion in Scala2 and disable the tests for Scala3 until we get it working. Nobody is meant to be calling new RequestBlob.FormEncodedRequestBlob in their application code using this library

[lolgab]

@lihaoyi Yeah, I get your point!
Let's move this test to src-2 and let's merge it!

[lihaoyi]

I moved all tests involving that implicit conversion to the src-2/ folder, let's see if CI is happy