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-milestone.svg

@@ -1 +1 @@
-<svg viewBox="0 0 14 16" class="svg octicon-milestone" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M8 2H6V0h2v2zm4 5H2c-.55 0-1-.45-1-1V4c0-.55.45-1 1-1h10l2 2-2 2zM8 4H6v2h2V4zM6 16h2V8H6v8z"/></svg>
+<svg viewBox="0 0 16 16" class="svg octicon-milestone" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M7.75 0a.75.75 0 01.75.75V3h3.634c.414 0 .814.147 1.13.414l2.07 1.75a1.75 1.75 0 010 2.672l-2.07 1.75a1.75 1.75 0 01-1.13.414H8.5v5.25a.75.75 0 11-1.5 0V10H2.75A1.75 1.75 0 011 8.25v-3.5C1 3.784 1.784 3 2.75 3H7V.75A.75.75 0 017.75 0zm0 8.5h4.384a.25.25 0 00.161-.06l2.07-1.75a.25.25 0 000-.38l-2.07-1.75a.25.25 0 00-.161-.06H2.75a.25.25 0 00-.25.25v3.5c0 .138.112.25.25.25h5z"/></svg>