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-diff.svg

@@ -1 +1 @@
-<svg viewBox="0 0 13 16" class="svg octicon-diff" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M6 7h2v1H6v2H5V8H3V7h2V5h1v2zm-3 6h5v-1H3v1zM7.5 2L11 5.5V15c0 .55-.45 1-1 1H1c-.55 0-1-.45-1-1V3c0-.55.45-1 1-1h6.5zM10 6L7 3H1v12h9V6zM8.5 0H3v1h5l4 4v8h1V4.5L8.5 0z"/></svg>
+<svg viewBox="0 0 16 16" class="svg octicon-diff" width="16" height="16" aria-hidden="true"><path fill-rule="evenodd" d="M8.75 1.75a.75.75 0 00-1.5 0V5H4a.75.75 0 000 1.5h3.25v3.25a.75.75 0 001.5 0V6.5H12A.75.75 0 0012 5H8.75V1.75zM4 13a.75.75 0 000 1.5h8a.75.75 0 100-1.5H4z"/></svg>