Local get_ss3_exe w/ gh::gh() token fix (refactor get_ss3_exe if-else platform/os)

[efletcherPIFSC]

Fix nmfs-ost SAML auth issues with found with #109 to implement r4ss::get_ss3_exe with gh::gh NA_character token fix

Create a local get_ss3_exe R script to maintain compatibility with r4ss 1.49.3 and implement gh::gh() token issue fixes (#109 (comment))

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os/platform if-else control statement for r4ss/r4ss get_ss3_exe can be optimized

The following the pseudo code for the if-else statement based on "current" implementation (at the time of issue was created) of get_ss3_exe

• If .Platform OS.type is windows
  • If r_arch is 32-bit then warn user "(Windows) 32-bit Stock Synthesis executable isn't available"
  • else download the target version (tag) of Stock Synthesis windows binary (ss3_win.exe) from nmfs-ost/ss3-source-code
• else
  • If (the first 6 characters of) R.version os matches "darwin" and R.version arch is "aarch64" then download the target version (tag) of Stock Synthesis binary (ss3_osx_arm64.exe) from nmfs-ost/ss3-source-code
  • else
    • If (the first 6 characters of) R.version os matches "darwin" and R.version arch is "x86_64" then download the target version (tag) of Stock Synthesis binary (ss3_osx.exe) from nmfs-ost/ss3-source-code
    • else
      • If .Platform OS.type is linux-gnu then download the target version tag of Stock Synthesis binary (ss3_linux) from nmfs-ost/ss3-source-code
      • else throw ss3 not available for platform error

Possible Solution

Unify control statements using R.version stating:

• match mingw32 for windows
• macOS: Check R.version$os the first 6 characters matches "darwin"
• match linux-gnu for linux
• throw error for other matchers

• IF Windows
  • 32-bit check
  • get ss3_win.exe
• ELSE IF "darwin" (macOS)
  • ss3_osx_arm64.exe
  • ss3_osx.exe
• ELSE IF "linux" get ss3_linux
• ELSE error