Investigate the "Size" option for creating data sets

[t1m0thyj]

Should we document the "Size" option, or consider removing it? I'm unsure how it gets used.

The typedoc for this option says it should not be sent to z/OSMF:

    /**
     * The abstraction of Allocation unit and Primary Space
     *
     * DO NOT SEND THIS TO ZOSMF
     *
     * @type {string}
     */
    size?: string;

And size is absent from the list of options documented by z/OSMF:
https://www.ibm.com/docs/en/zos/2.4.0?topic=interface-create-sequential-partitioned-data-set#CreateDataSet

[JWaters02]

Yeah I never really knew what that size field is actually referring to.

[zFernand0]

After some discussion with both (CLI and ZE) squads, we determine that it might be best to expose the mechanism for deconstructing the size property as a new SDK method. This will allow Zowe Explorer to remove the property from this list, and always populate primary and secondary according to the same rules as the CLI 😋

For details, see:

• SDK: Expose size allocation property as an API to obtain primary and secondary values zowe-cli#2521