pkg: add req, http-client, http-types dependencies; begin HTTP support

hledger can now make HTTP requests over the network.
For now, it makes just one (in following commits):
checking Hackage for the current hledger release version.

hledger/hledger.cabal

@@ -170,6 +170,8 @@ library
     , hashable >=1.2.4
     , haskeline >=0.6
     , hledger-lib >=1.42.99 && <1.43
+    , http-client
+    , http-types
     , lucid
     , math-functions >=0.3.3.0
     , megaparsec >=7.0.0 && <9.8
@@ -178,6 +180,7 @@ library
     , mtl >=2.2.1
     , process
     , regex-tdfa
+    , req
     , safe >=0.3.20
     , shakespeare >=2.0.2.2
     , split >=0.1
@@ -223,12 +226,15 @@ executable hledger
     , haskeline >=0.6
     , hledger
     , hledger-lib >=1.42.99 && <1.43
+    , http-client
+    , http-types
     , math-functions >=0.3.3.0
     , megaparsec >=7.0.0 && <9.8
     , microlens >=0.4
     , mtl >=2.2.1
     , process
     , regex-tdfa
+    , req
     , safe >=0.3.20
     , shakespeare >=2.0.2.2
     , split >=0.1
@@ -273,12 +279,15 @@ test-suite unittest
     , haskeline >=0.6
     , hledger
     , hledger-lib >=1.42.99 && <1.43
+    , http-client
+    , http-types
     , math-functions >=0.3.3.0
     , megaparsec >=7.0.0 && <9.8
     , microlens >=0.4
     , mtl >=2.2.1
     , process
     , regex-tdfa
+    , req
     , safe >=0.3.20
     , shakespeare >=2.0.2.2
     , split >=0.1
@@ -322,12 +331,15 @@ benchmark bench
     , hledger
     , hledger-lib >=1.42.99 && <1.43
     , html
+    , http-client
+    , http-types
     , math-functions >=0.3.3.0
     , megaparsec >=7.0.0 && <9.8
     , microlens >=0.4
     , mtl >=2.2.1
     , process
     , regex-tdfa
+    , req
     , safe >=0.3.20
     , shakespeare >=2.0.2.2
     , split >=0.1

hledger/package.yaml

@@ -136,11 +136,14 @@ dependencies:
 - filepath
 - githash >=0.1.6.2
 - haskeline >=0.6
+- http-client
+- http-types
 - megaparsec >=7.0.0 && <9.8
 - microlens >=0.4
 - mtl >=2.2.1
 - process
 - regex-tdfa
+- req
 - safe >=0.3.20
 - shakespeare >=2.0.2.2
 - split >=0.1