api: support getting repository Git tree (#5934) (#5937)

* add basic git repository tree api (#5934)

This PR adds the tree  api endpoint to gogs api:
`GET/repos/:owner/:repo/git/trees/:tree_sha`

This new api endpoint that is being added is in conformance to
the GitHub REST API v3 specification. Documentation can be found
here: developer.github.com/v3/git/trees/#get-a-tree

For a given user, repo and sha value, this api (currently) returns
a single tree using the SHA1 value for that tree.

- Recursive implementation is yet to be implemented.
- Creating a Tree using POST is yet to be implemented.

Example curl:

```

l curl -H "Authorization: token REDACTED" http://localhost:3000/api/v1/repos/root/testrepo/git/trees/c59441ded1549b149def0d4c54594d31a7f3718f -X GET  | jq .
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   940  100   940    0     0  12034      0 --:--:-- --:--:-- --:--:-- 12051

[
  {
    "sha": "c59441ded1549b149def0d4c54594d31a7f3718f",
    "tree": [
      {
        "mode": "120000",
        "path": "/home/bharatnc/gogs-repositories/root/testrepo.git",
        "sha": "472ac2361b65136b393d652de25341e2ea44f299",
        "size": 1077,
        "type": "blob",
        "url": "http://localhost:3000/api/v1/repos/root/testrepo/git/trees/472ac2361b65136b393d652de25341e2ea44f299"
      },
      {
        "mode": "120000",
        "path": "/home/bharatnc/gogs-repositories/root/testrepo.git",
        "sha": "70fcb456d436f08462602f26df6fb7e167e7a916",
        "size": 12,
        "type": "blob",
        "url": "http://localhost:3000/api/v1/repos/root/testrepo/git/trees/70fcb456d436f08462602f26df6fb7e167e7a916"
      },
      {
        "mode": "120000",
        "path": "/home/bharatnc/gogs-repositories/root/testrepo.git",
        "sha": "092c58d4b63df5779a4d020b1fdbb762421bbb4f",
        "size": 380,
        "type": "blob",
        "url": "http://localhost:3000/api/v1/repos/root/testrepo/git/trees/092c58d4b63df5779a4d020b1fdbb762421bbb4f"
      }
    ],
    "url": "http://localhost:3000/api/v1/repos/root/testrepo/git/trees/c59441ded1549b149def0d4c54594d31a7f3718f"
  }
]

```

* remove vertical space

* make go.mod to be same as in master

* rename structs to sound better

* simplify expressions and fix error msg

* Update tree.go

* Update tree.go

* display file name instead of repo path

* Update tree.go

Co-authored-by: ᴜɴᴋɴᴡᴏɴ <u@gogs.io>

0 files changed, 0 insertions, 0 deletions