Add additional options to User Metadata

[ndiego]

Ported over from WordPress.org.

The list of available options for “Show the block if User Metadata…” are:

• Has any value
• Has no value
• Value is equal to
• Value is not equal to
• Value contains
• Value does not contain

If the meta field contains numeric data, it would be helpful to choose block visibility if the meta

• “value is equal to or greater than”
• “value is equal to or less than”

Alternatively, if the “Enter meta value” field could accept arguments like “<=1” instead of just integers, that could work perhaps?

That would then allow the existing 6 options to suffice, because I could choose option 3 and then enter “<=1” instead of just “1”