py/objstr: Consolidate methods for str/bytes/bytearray/array.

This commit adds the bytes methods to bytearray, matching CPython.  The
existing implementations of these methods for str/bytes are reused for
bytearray with minor updates to match CPython return types.

For details on the CPython behaviour see
https://docs.python.org/3/library/stdtypes.html#bytes-and-bytearray-operations

The work to merge locals tables for str/bytes/bytearray/array was done by
@jimmo.  Because of this merging of locals the change in code size for this
commit is mostly negative:

       bare-arm:    +0 +0.000%
    minimal x86:   +29 +0.018%
       unix x64:  -792 -0.128% standard[incl -448(data)]
    unix nanbox:  -436 -0.078% nanbox[incl -448(data)]
          stm32:   -40 -0.010% PYBV10
         cc3200:   -32 -0.017%
        esp8266:   -28 -0.004% GENERIC
          esp32:   -72 -0.005% GENERIC[incl -200(data)]
         mimxrt:   -40 -0.011% TEENSY40
     renesas-ra:   -40 -0.006% RA6M2_EK
            nrf:   -16 -0.009% pca10040
            rp2:   -64 -0.013% PICO
           samd:  +148 +0.105% ADAFRUIT_ITSYBITSY_M4_EXPRESS

1 files changed, 13 insertions, 0 deletions

diff --git a/tests/basics/bytes_center.py b/tests/basics/bytes_center.py
new file mode 100644
index 0000000000..5d8b41d92f
--- /dev/null
+++ b/tests/basics/bytes_center.py
@@ -0,0 +1,13 @@
+try:
+    bytes.center
+except:
+    print("SKIP")
+    raise SystemExit
+
+print(b"foo".center(0))
+print(b"foo".center(1))
+print(b"foo".center(3))
+print(b"foo".center(4))
+print(b"foo".center(5))
+print(b"foo".center(6))
+print(b"foo".center(20))