Fix python script to generate .view file and other small fixes

[mo-jmanners]

PR Summary

Sci/Tech Reviewer:
Code Reviewer: @jennyhickson

Small bug-fixes originally included in #16:

• Correct output for the level dimension in nctools, used to create the .view file in the wiki tutorial: Example spherical harmonics radiance calculation
• Read the filename as a string in make_block_17 (prevents failures when certain filepaths are provided).
• gitignore the bin directory: prevents problems using a working copy in the LFRic build

Code Quality Checklist

(Some checks are automatically carried out via the CI pipeline)

• I have performed a self-review of my own code
• My code follows the project's style guidelines
• Comments have been included that aid undertanding and enhance the
  readability of the code
• My changes generate no new warnings

Testing

• If shared files have been modified, I have run the UM and LFRic Apps rose
  stem suites
• If any tests fail (rose-stem or CI) the reason is understood and
  acceptable (eg. kgo changes)
• I have added tests to cover new functionality as appropriate (eg. system
  tests, unit tests, etc.)

• UM and LFRic testing is not required as no files have been affected that are used in their builds.
• Socrates stand-alone quick_tests and slow_tests pass:

Testing code compiled in /home/users/james.manners/git/socrates_admin/bin
---
Testing simple calls to the runes interface:
Matched gfortran output
OK
---
Testing the runes_nc driver using LFRic diagnostic input:
Matched SW output
Matched LW output
OK
---
Testing raw_input to convert column data into input files:
OK
---
Testing Cl_run_cdl for ICRCCM case 27 (LW) on AER profiles:
OK
---
Testing Cl_run_cdf on multiple profiles:
OK
---
Test Cl_run_cdf for CIRC case 6
(HadGEM, GA7, SES and 300/260 band spectral files):
OK
---
Testing pseudo-spherical geometry code:
Calculating zenith angles:  75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98
OK
---
Testing photolysis and non-LTE code:
Mapping sub-bands to channels.
Matched gfortran output
OK
---
Test McICA code (create mcica_data file and run on CRM profile):
OK
---
Testing creation of aerosol properties for a spectral file:
Running scatter_90...
Running scatter_average_90...
Running prep_spec...
Matched gfortran12 output
OK
---
Testing generating and running with prescribed optical properties:
Running raw_input...
Running Cscatter... please wait...
Running Cscatter... please wait...
Running Cscatter_average...
Running Cscatter_average...
Running prep_opt_profile...
Running Cl_run_cdl...
All done.
OK
---
Testing Crun_mono to calculate radiances:
Matched ref output
OK
---
Testing Ccorr_k to generate correlated-k coefficients:
Matched gfortran12 output
OK
---
Testing flexchem chemistry:
Matched KGO output
OK
---
Testing CDL scripts:
OK
---
All passed.

Security Considerations

• I have reviewed my changes for potential security issues
• Sensitive data is properly handled (if applicable)
• Authentication and authorisation are properly implemented (if applicable)

Performance Impact

• Performance of the code has been considered and, if applicable, suitable
  performance measurements have been conducted

AI Assistance and Attribution

• Some of the content of this change has been produced with the assistance
  of Generative AI tool name (e.g., Met Office Github Copilot Enterprise,
  Github Copilot Personal, ChatGPT GPT-4, etc) and I have followed the
  Simulation Systems AI policy
  (including attribution labels)

Documentation

• Where appropriate I have updated documentation related to this change and
  confirmed that it builds correctly

Sci/Tech Review

• I understand this area of code and the changes being added
• The proposed changes correspond to the pull request description
• Documentation is sufficient (do documentation papers need updating)
• Sufficient testing has been completed

Please alert the code reviewer via a tag when you have approved the SR

Code Review

• All dependencies have been resolved
• Related Issues have been properly linked and addressed
• CLA compliance has been confirmed
• Code quality standards have been met
• Tests are adequate and have passed
• Documentation is complete and accurate
• Security considerations have been addressed
• Performance impact is acceptable

[jennyhickson]

This all looks sensible. Thanks.