VPMenuLink does not handle regex for activeMatch

[peterhpchen]

Describe the bug

VPMenuLink does not handle regex for activeMatch.

Reproduction

Please see this StackBlitz:

1. Click Dropdown Menu > Item A. The Item A of the Dropdown Menu is active.
2. Click Next Page to go to second page. The Item A of the Dropdown Menu is inactive.the

Expected behavior

The Item A in the Nav should be active on both pages.

System Info

System:
    OS: macOS 13.0.1
    CPU: (8) x64 Intel(R) Core(TM) i5-8257U CPU @ 1.40GHz
    Memory: 26.19 MB / 16.00 GB
    Shell: 5.8.1 - /bin/zsh
  Binaries:
    Node: 18.12.0 - ~/.config/nvm/versions/node/v18.12.0/bin/node
    Yarn: 1.22.19 - ~/.config/nvm/versions/node/v18.12.0/bin/yarn
    npm: 8.19.2 - ~/.config/nvm/versions/node/v18.12.0/bin/npm
  Browsers:
    Chrome: 108.0.5359.124
    Safari: 16.1
  npmPackages:
    vitepress: ^1.0.0-alpha.35 => 1.0.0-alpha.35 

Additional context

I think we should add the third parameter to the function isActive in the component VPMenuLink because it handles the regex.

vitepress/src/client/theme-default/components/VPMenuLink.vue

Line 16 in 01ac579

:class="{ active: isActive(page.relativePath, item.activeMatch || item.link) }"

Just like VPNavBarMenuGroup:

vitepress/src/client/theme-default/components/VPNavBarMenuGroup.vue

Line 21 in 01ac579

!!item.activeMatch

Validations

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