Modernize python and update pylint (#5096)

Update code to conform to the newer version of pylint available in
ubuntu-22.04, with few exceptions:
    - disabled `import-outside-toplevel` for `main()` in
      `jerry_client.py`
    - disabled `consider-using-with` for the logfile of `TestSuite` in
      `test262-harness.py` as using `with` is not practical in that case

Update test262-harness.py to use argparse instead of the now deprecated
optparse

Rename variables in jerry_client_main.py that redefined python builtins
or shadowed variables from an outer scope

Update python files to use f-stirngs

Add minimum python versions (3.6 and 3.8) to the CI jobs: without it the
default python version did not support the `with` statement for
`subprocess.Popen` used in `build.py` on macos, or in some cases f-stirngs

Remove `from __future__` imports that are no-ops in python 3

Remove shebang from non executable files

Re-enable most pylint checkers, except `missing-docstring`

JerryScript-DCO-1.0-Signed-off-by: Máté Tokodi mate.tokodi@szteszoftver.hu

tools/heaplimit_measure.py

@@ -13,9 +13,6 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-from __future__ import print_function
-# force // operator to be integer division in Python 2
-from __future__ import division
 
 import argparse
 import json
@@ -53,7 +50,7 @@ def check_files(opts):
     files = [JERRY_BUILDER, opts.testfile]
     for _file in files:
         if not os.path.isfile(_file):
-            sys.exit("File not found: %s" % _file)
+            sys.exit(f"File not found: {_file}")
 
 
 def build_bin(heapsize, opts):
@@ -68,7 +65,7 @@ def build_bin(heapsize, opts):
     if opts.buildtype == 'debug':
         command.append(FLAG_DEBUG)
 
-    print('Building JerryScript with: %s' % (' '.join(command)))
+    print(f"Building JerryScript with: {' '.join(command)}")
     subprocess.check_output(command)