Allow licenses with a 10% overage of users for renewals

What does this MR do?

Part of #333851 (closed)

There already was a 10% overage allowance on users count when applying a new license (no renewals). Now, the same overage will be applied to all license uploads for the users count including renewals.

How to setup and validate locally (strongly suggested)

For new license: Create a license that is for less than the users in your instance but would meet the count when adding 10% to it. In my tests, the instance had 52 users, so the created license had 48 users (10% are 4 users so 52 would be met).

For renewal: Do the same but create the license with a number in Previous users count, in my case that was 40.

Then try uploading the licenses.

Does this MR meet the acceptance criteria?

Conformity

• I have included changelog trailers, or none are needed. (Does this MR need a changelog?)
• I have added/updated documentation, or it's not needed. (Is documentation required?)
• I have properly separated EE content from FOSS, or this MR is FOSS only. (Where should EE code go?)
• I have added information for database reviewers in the MR description, or it's not needed. (Does this MR have database related changes?)
• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.
• This change is backwards compatible across updates, or this does not apply.

Availability and Testing

• I have added/updated tests following the Testing Guide, or it's not needed. (Consider all test levels. See the Test Planning Process.)
• I have tested this MR in all supported browsers, or it's not needed.
• I have informed the Infrastructure department of a default or new setting change per definition of done, or it's not needed.

Security

Does this MR contain changes to processing or storing of credentials or tokens, authorization and authentication methods or other items described in the security review guidelines? If not, then delete this Security section.

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team