Update Octicons to v10 (#12240)

* Update Octicons to v10

Besides a few renames, these icons are no longer present in v10 that we've
used, so had to change:

file-symlink-directory -> file-submodule
internal-repo -> repo
repo-force-push -> repo-push
repo-template-private -> repo-template

Fixes: https://github.com/go-gitea/gitea/issues/11889
Ref: https://github.com/primer/octicons/releases/tag/v10.0.0

* add custom sliders svg for removed octicon-settings

* apply suggestion

* fix triangles and use play on admin dashboard

* add custom mirror svg

* add missing build files

* unify custom svgs

* move to octicon-repo-clone to gitea-mirror

* use octicon-x on conflicts

* tweak timeline icons

* tweak comment buttons

* update settings icon to octicons v1

* switch to octicon-mirror and octicon-tools

* replace two wiki buttons with octicons

* remove whitespace in svg sources

* Fix filepath basename on Windows for SVG bindata (#12241)

* move octicons to devDependencies

* move back to dependencies

* move svgo to devDependencies again

Co-authored-by: Cirno the Strongest <1447794+CirnoT@users.noreply.github.com>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

public/img/svg/octicon-link-external.svg

@@ -1 +1 @@
-<svg viewBox="0 0 12 16" class="svg octicon-link-external" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M11 10h1v3c0 .55-.45 1-1 1H1c-.55 0-1-.45-1-1V3c0-.55.45-1 1-1h3v1H1v10h10v-3zM6 2l2.25 2.25L5 7.5 6.5 9l3.25-3.25L12 8V2H6z"/></svg>
+<svg viewBox="0 0 16 16" class="svg octicon-link-external" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M10.604 1h4.146a.25.25 0 01.25.25v4.146a.25.25 0 01-.427.177L13.03 4.03 9.28 7.78a.75.75 0 01-1.06-1.06l3.75-3.75-1.543-1.543A.25.25 0 0110.604 1zM3.75 2A1.75 1.75 0 002 3.75v8.5c0 .966.784 1.75 1.75 1.75h8.5A1.75 1.75 0 0014 12.25v-3.5a.75.75 0 00-1.5 0v3.5a.25.25 0 01-.25.25h-8.5a.25.25 0 01-.25-.25v-8.5a.25.25 0 01.25-.25h3.5a.75.75 0 000-1.5h-3.5z"/></svg>