Added support for semicolon-separated value files

[Aritra8438]

This PR Fixes #2753

Technical details:
Currently Mathesar allows importing DSV files with following delimiters:
,
\t
:
|
This pull request adds support for importing semicolon ; separated values files as well.

Additional references:
Mathesar uses clevercsv to detect the possible delimiter(s) of a file.
from the docs, I have noted the following definitions that might be relevant.

• block_char (iterable) – Characters that are in the Punctuation Other category but that
  should not be considered as escape character. If None, the default set is used, equal to:
  "!", "?", '"', "'", ".", ",", ";", ":", "%", "*"

• quote_chars (iterable) – Characters that should be considered quote characters. If it is
  None, the following default set is used:
  "'", '"', "~", ""`

• delimiters (iterable) – List of delimiters to consider. If None, the get_delimiters() function is used to automatically detect the delimiter

Semicolon is included in the set of block_chars, that means it's a potential candidate for being a delimiter.

Apart from that, I have tested the underlying logic of selecting delimiter for a given file on Google Colab and am attaching the same with this pull request to get this verified by you.

Checklist

• My pull request has a descriptive title (not a vague title like Update index.md).
• My pull request targets the develop branch of the repository
• My commit messages follow best practices.
• My code follows the established code style of the repository.
• I added tests for the changes I made (if applicable).
• I added or updated documentation (if applicable).
• I tried running the project locally and verified that there are no
  visible errors.

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[Aritra8438]

Also, attaching a screencast of the working feature,

dsv.mp4

[Aritra8438]

Hi, @rajatvijay. Should I do anything about the failure of Run Python Tests?

[dmos62]

@Aritra8438 yes, please fix the failing test/s.

[Aritra8438]

@Aritra8438 yes, please fix the failing test/s.

I have fixed it.