Rename proprietary-license_87 and proprietary-license_597 to HESSLA

**License Name**

https://github.com/aboutcode-org/scancode-toolkit/blob/develop/src/licensedcode/data/rules/proprietary-license_87.RULE

and

https://github.com/aboutcode-org/scancode-toolkit/blob/develop/src/licensedcode/data/rules/proprietary-license_597.RULE

are the HESSLA license, but with an extra introductory statement.

https://github.com/aboutcode-org/scancode-toolkit/blob/develop/src/licensedcode/data/licenses/hessla.LICENSE

Possible remedies:

1. rename the proprietary licenses to HESSLA
2. add the introductory statement to HESSLA as a separate rule, deprecate these two proprietary licenses

Comments from @pombredanne and @AyanSinhaMahapatra would be appreciated.