Reland "[PA] Introduce PartitionTlsRegistry to track PartitionTls instances"

This reverts commit 9467d08d9e085700a4e184f5ff22568291b718eb.

Reason for revert: Parent CL relanded https://crrev.com/c/8483734

Original change's description:
> Revert "[PA] Introduce PartitionTlsRegistry to track PartitionTls instances"
>
> This reverts commit 33ce22068bdb197fc227e9313a5d49432b30bd6b.
>
> Reason for revert: Dependent on CL chain suspected to cause memory regression
>
> Failure Link: https://pinpoint-dot-chromeperf.appspot.com/job/157bfe49690000
>
> Original change's description:
> > [PA] Introduce PartitionTlsRegistry to track PartitionTls instances
> >
> > With this, we can iterate through active `PartitionTls` members.
> >
> > Change-Id: Id7b0ed89c768cf70b351e00e6ab521377c78f372
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/8366011
> > Commit-Queue: Mikihito Matsuura <mikt@google.com>
> > Reviewed-by: Takashi Sakamoto <tasak@google.com>
> > Cr-Commit-Position: refs/heads/main@{#1695581}
>
> Change-Id: I5e7d58532c3789beb8433234c157057ede2575e5
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/8413365
> Owners-Override: Anna Tsvirchkova <atsvirchkova@google.com>
> Bot-Commit: rubber-stamper@appspot.gserviceaccount.com <rubber-stamper@appspot.gserviceaccount.com>
> Reviewed-by: Mateusz Zbikowski <zbikowski@google.com>
> Commit-Queue: Alex Mitra <alexmitra@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1698070}

Change-Id: I3e88ab4606858b0ee5e3aa46d89afa9ee7be056f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/8494351
Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
Commit-Queue: Mikihito Matsuura <mikt@google.com>
Cr-Commit-Position: refs/heads/main@{#1713331}
NOKEYCHECK=True
GitOrigin-RevId: a52590b208ce1cf2d64865443c3f2e6acf29af6b