LFS support to be stored on minio

[lunny]

As a next step of #11387, Fix #5530

[codecov-commenter]

Codecov Report

Merging #12518 into master will decrease coverage by 0.03%.
The diff coverage is 25.94%.

@@            Coverage Diff             @@
##           master   #12518      +/-   ##
==========================================
- Coverage   43.30%   43.26%   -0.04%     
==========================================
  Files         647      648       +1     
  Lines       71800    71886      +86     
==========================================
+ Hits        31090    31099       +9     
- Misses      35675    35745      +70     
- Partials     5035     5042       +7     

Impacted Files	Coverage Δ
cmd/migrate_storage.go	0.00% <0.00%> (ø)
modules/repofiles/update.go	40.30% <0.00%> (-0.31%)	⬇️
modules/repofiles/upload.go	0.00% <0.00%> (ø)
routers/repo/lfs.go	0.00% <0.00%> (ø)
modules/storage/minio.go	48.43% <5.00%> (-20.46%)	⬇️
models/lfs.go	22.64% <11.76%> (-2.08%)	⬇️
modules/lfs/server.go	43.85% <23.07%> (-1.69%)	⬇️
modules/storage/storage.go	44.44% <30.76%> (-12.70%)	⬇️
modules/setting/lfs.go	41.86% <41.86%> (ø)
modules/lfs/content_store.go	50.00% <57.14%> (+1.66%)	⬆️
... and 13 more

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[zeripath]

Is there really no way to make these self-register?

[lunny]

I don't know. But the current codes look clear and simple.

[lafriks]

Do we really need duplicate minio configuration for each type of data stored in it? Should different buckets would not be enaugh

[techknowlogick]

@lafriks some users may wish to use cheaper s3 providers for avatars, and then more robust s3 provider for LFS

[lunny]

@lafriks I will send another PR to add a storage config so that attachments, avatar, lfs could inherit from that if they don't configure that.

[zeripath]

hmm... I'm wondering if we'd be better off calving off the storage options into:

[storage] ; this is the default storage option
TYPE=local
PATH=/data ; specific storage will inherit from this as a subpath

[storage.attachments]
TYPE=local; minio or the like
; PATH would default to [storage] PATH/attachments
... ; specific storage content config

[storage.lfs]
TYPE=local; minio or the like
... ; specific storage content config

...

Then we can move the specific configuration to the storage module and do something like queues configuration stuff.

[lunny]

@zeripath Yes, that's my next PR. But I will only add [storage] and keep other configuration on [attchements], [lfs] and etc.