Check for architecture existing in python

[verylazyguy]

Version and Platform (required):

• Binary Ninja Version: [5.2.8573
• Edition: Commercial
• OS: MacOS
• OS Version: 26.1
• CPU Architecture: M2

Bug Description:
Have to try/catch to see if an architecture is loaded

Steps To Reproduce:

>>> "aarch64" in Architecture
False
>>> Architecture["aarch64"]
<arch: aarch64>
>>> Architecture.get("aarch64")
Traceback (most recent call last):
  File "<console>", line 1, in <module>
AttributeError: type object 'Architecture' has no attribute 'get'

Expected Behavior:

>>> "aarch64" in Architecture
True
>>> Architecture["aarch64"]
<arch: aarch64>