[IMP] Inventory: Bringing Closest location removal strategy current

[erjer-odoo]

While working on the removal strategies overview script, I realized that our "Closest Location" removal strategy documentation was slightly out-of-date. In this PR, I did the following:

• Added a section to enable the strategy
• Moved location names content into its own subheading
• Moved removal strategy setting to its own subheading and added a screenshot
• Updated language to be current with 18.3 forward
• Updated relevant screenshots to match 18.3 language

This required less work than the other removal strategy docs, so I labeled it accordingly.

This saas-18.3 PR can be FWP up to master.