Updates to aop_download to include skip_if_exists and overwrite options

[bhass-neon]

New functionality in AOP to check if files exist with logic explained below:

skip_if_exists
If skip_if_exists=True:

• The function checks if each file already exists locally.
• If a file does not exist locally, it is downloaded.
• If a file exists and its checksum matches the latest version on the NEON Data Portal, it is skipped (not downloaded again).
• If a file exists but its checksum does not match, the function will either prompt you, skip, or overwrite it—depending on the overwrite option (y/n/prompt)

If skip_if_exists=False:

• The function does not check for existing files or their checksums.
• All files are downloaded and will overwrite any existing files by default.

overwrite
This option only applies if skip_if_exists=True. This determines what happens when a file exists locally but its checksum does not match the latest published version on the NEON Data Portal

• overwrite='yes': Overwrite mismatched files automatically (no prompt).
• overwrite='no': Skip mismatched files (do not overwrite, no prompt).
• overwrite='prompt' (default): Prompt the user to decide whether to overwrite each mismatched file.

Notes:

• If skip_if_exists=False, the overwrite option is ignored and all files are overwritten, according to the default function behavior (assuming no pre-existing files in the expected folder). A warning message appears if skip_if_exists=False and overwrite='yes' or 'no'.
• If there are additional files in the expected folder, a warning message will appear for by_file_aop only. For by_tile_aop, there may be a different # of folders depending on the easting, northing and buffer that are used.