Add "new issue" btn on project

[romdum]

To solve #14824.

I added a button at left of "New Project Board" to create an issue from project view.

As suggest in issue #14824, it's possible to move "New Project Board" button at right of boards.

[codecov-commenter]

Codecov Report

Merging #17001 (7501bd9) into main (4c7a70b) will increase coverage by 0.04%.
The diff coverage is 47.94%.

@@            Coverage Diff             @@
##             main   #17001      +/-   ##
==========================================
+ Coverage   45.17%   45.22%   +0.04%     
==========================================
  Files         762      766       +4     
  Lines       86174    86579     +405     
==========================================
+ Hits        38932    39156     +224     
- Misses      40948    41088     +140     
- Partials     6294     6335      +41     

Impacted Files	Coverage Δ
cmd/doctor.go	0.00% <ø> (ø)
models/attachment.go	57.89% <0.00%> (-0.68%)	⬇️
modules/migrations/gitea_downloader.go	0.88% <0.00%> (-0.01%)	⬇️
modules/migrations/migrate.go	27.79% <ø> (ø)
modules/setting/repository.go	58.49% <ø> (ø)
modules/storage/minio.go	58.18% <0.00%> (ø)
modules/templates/helper.go	51.36% <0.00%> (ø)
routers/api/v1/repo/migrate.go	44.17% <0.00%> (ø)
routers/api/v1/repo/mirror.go	0.00% <0.00%> (ø)
routers/api/v1/repo/pull.go	29.08% <0.00%> (-0.16%)	⬇️
... and 40 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 0faf175...7501bd9. Read the comment docs.

[6543]

a followup would be: after issue creation was sucessfull, redirect back to project