Add directdownload endpoint

[rullzer]

Fixes #9142

A basic endpoint to allow clients to have an easy streaming endpoint (for example opening a file in VLC).

1. post request is made to <server>/ocs/v2.php/apps/dav/api/v1/direct with fileId=<x>
2. A link is returned
3. This link is used by the client to stream

We first ask the storage for a link (S3 for example could provide this directly). Otherwise we generate a 60 char token.

The link thus only gives read access for a limited time.
The link is read only (of course)
The link is more than unique enough (just check 62^60)

Todo:

• Links are valid for 8 hours. However after those 8 hours a request shoudl not directly trigger bruteforce protection.
• Cleanup tokens expired more than a day ago in a cron job.
• Some error handling
• Tests

[rullzer]

@tobiasKaminsky

[nickvergessen]

Can I haz hooks for activities 🤓

[rullzer]

@nickvergessen o yes please that would be awesome!

[rullzer]

@nickvergessen when do you want the hooks? On creation or on access? (or both?)

[codecov]

Codecov Report

Merging #9178 into master will decrease coverage by 0.01%.
The diff coverage is 46.97%.

@@             Coverage Diff              @@
##             master    #9178      +/-   ##
============================================
- Coverage     51.92%   51.91%   -0.02%     
- Complexity    25388    25429      +41     
============================================
  Files          1608     1618      +10     
  Lines         95429    95644     +215     
  Branches       1394     1394              
============================================
+ Hits          49555    49656     +101     
- Misses        45874    45988     +114

Impacted Files	Coverage Δ	Complexity Δ
apps/dav/composer/composer/autoload_static.php	0% <ø> (ø)	1 <0> (ø)	⬇️
apps/dav/lib/Direct/Server.php	0% <0%> (ø)	1 <1> (?)
remote.php	0% <0%> (ø)	0 <0> (ø)	⬇️
...av/lib/Migration/Version1005Date20180413093149.php	0% <0%> (ø)	2 <2> (?)
apps/dav/appinfo/v2/direct.php	0% <0%> (ø)	0 <0> (?)
apps/dav/lib/Direct/ServerFactory.php	0% <0%> (ø)	2 <2> (?)
apps/dav/composer/composer/autoload_classmap.php	0% <0%> (ø)	0 <0> (ø)	⬇️
apps/dav/appinfo/routes.php	0% <0%> (ø)	0 <0> (ø)	⬇️
apps/dav/lib/Db/DirectMapper.php	10% <10%> (ø)	4 <4> (?)
apps/dav/lib/Db/Direct.php	100% <100%> (ø)	1 <1> (?)
... and 14 more

[rullzer]

Ok let do this. I can add the activity hooks later.

@tobiasKaminsky already played around with it on android and it seems to do the job ;)

[tobiasKaminsky]

Yes, from my side it is working :-)

[MorrisJobke]

🐘