area/ui: fix bug in relative range picker

[yomete]

This fixes a bug where typing something like 1w in the relative range picker and then hitting enter resets the input to 15m. This was happening because we were not handling cases for where users are typing in week ranges. This has been added now.

[alwaysmeticulous[bot]]

🤖 Meticulous spotted visual differences in 24 of 524 screens tested: view and approve differences detected.

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